User Authorization Technique

1. A computer-readable medium encoded with computer-executable instructions for authorizing a visitor to a web site, the instructions comprising:

receiving a request to access a secure resource identified by a locator;

evaluating the locator to identify an authorization code within the locator that indicates the request is authorized to retrieve the resource;

determining if the authorization code has already been used to authorize the retrieval of the resource; and

if the authorization code has not already been used to authorize a prior request, allowing the access to the secure resource without first prompting for login credentials and transmitting persistent data to the requester for use in subsequent requests to access the secure resource.

2. The computer-readable medium recited in claim 1, wherein the locator comprises a Uniform Resource Locator and the persistent data comprises a cookie.

3. The computer-readable medium recited in claim 1, wherein the authorization code comprises a message ID and a counter, the message ID identifying a particular message, the counter identifying a particular instance of the particular message.

4. The computer-readable medium recited in claim 3, wherein the particular message comprises an e-mail message.

5. The computer-readable medium recited in claim 1, further comprising:

if the authorization code has already been used to authorize a prior request, rejecting the request.

6. The computer-readable medium recited in claim 5, wherein rejecting the request comprises prompting for a requester e-mail address, and comparing the e-mail address with information that associates the authorization code with an authorized e-mail address.

7. The computer-readable medium recited in claim 6, further comprising, if the requester e-mail address matches the authorized e-mail address, creating a new authorization code based on the authorized e-mail address and transmitting the new authorization code to the requester e-mail address.

8. The computer-readable medium recited in claim 1, wherein determining if the authorization code has already been used comprises evaluating an authorization table that includes records for each authorization code, each record including a field that contains a value to indicate whether the authorization code has been used.

9. The computer-readable medium recited in claim 1, wherein the secure resource comprises personal pages associated with a social networking service.

10. A computer-readable medium encoded with computer-executable components for authorizing a visitor to a web site, the components comprising:

an authorization engine to authorize requests for secure resources stored on a server, the authorization engine being configured to:

create a URL including an authorization code including a message ID and a counter, the message ID being uniquely associated with a particular message, the counter being associated with a particular instance of the particular message;

transmit an electronic message having a link to a secure resource, the link identifying a location of the secure resource and including the authorization code.

11. The computer-readable medium recited in claim 10, wherein the authorization engine is further configured to:

receive a request to access the secure resource at the location identified by the link, the request including the authorization code;

extract the authorization code from the request;

compare the authorization code to data stored in an authorization table, the data indicating whether the authorization code has been used in a prior request for access to the secure resource; and

if the authorization code has not been used to authorize a prior request, allow the access to the secure resource without first prompting for login credentials and transmit persistent data to the requester for use in subsequent requests to access the secure resource.

12. The computer-readable medium recited in claim 10, wherein the link comprises a Uniform Resource Locator and the persistent data comprises a cookie.

13. The computer-readable medium recited in claim 11, wherein the authorization engine is further configured to:

if the authorization code has already been used to authorize a prior request, reject the request.

14. The computer-readable medium recited in claim 13, wherein the authorization engine is further configured to reject the request by prompting for a requester e-mail address, and comparing the e-mail address with information that associates the authorization code with an authorized e-mail address.

15. The computer-readable medium recited in claim 14, wherein if the requester e-mail address matches the authorized e-mail address, the authorization engine is further configured to create a new authorization code based on the authorized e-mail address and to transmit the new authorization code to the requester e-mail address.

16. The computer-readable medium recited in claim 11, wherein the authorization engine is further configured to determine if the authorization code has already been used by evaluating an authorization table that includes records for each authorization code, each record including a field that contains a value to indicate whether the authorization code has been used.

17. The computer-readable medium recited in claim 11, wherein the secure resource comprises personal pages associated with a social networking service.

18. A method for authorizing a visitor to a web site, comprising:

receiving a request to access a secure resource identified by a locator;

evaluating the locator to identify an authorization code within the locator that indicates the request is authorized to retrieve the resource;

determining if the authorization code has already been used to authorize the retrieval of the resource; and

if the authorization code has not already been used to authorize a prior request:

storing an indication that the authorization code has been used in an authorization table,

storing an IP address associated with the request, and

allowing the access to the secure resource without first prompting for login credentials.

19. The method recited in claim 18, wherein determining if the authorization code has already been used to authorize the retrieval of the resource comprises comparing the IP address associated with the request with a stored IP address in an authorization table, the stored IP address being associated with a prior request to access the secure resource.

20. The method recited in claim 18, wherein the locator comprises a Uniform Resource Locator.