9. The method of claim 1 wherein: accessing, from a computer memory storage system, multiple pieces of content includes accessing, from the computer memory storage system, an index of multiple pieces of content; comparing the indication of the topic of interest to the multiple pieces of content accessed from the computer memory storage system includes searching the index for content that matches at least a portion of the indication of the topic of interest; and identifying a piece of content as being relevant to the topic of interest based on results of comparing the indication of the topic of interest to the multiple pieces of content accessed from the computer memory storage system includes identifying a piece of content as being relevant to the topic of interest based on results of searching the index for content that matches at least a portion of the indication of the topic of interest.
9. The method of claim 1 wherein: accessing, from a computer memory storage system, multiple pieces of content includes accessing, from the computer memory storage system, an index of multiple pieces of content; comparing the indication of the topic of interest to the multiple pieces of content accessed from the computer memory storage system includes searching the index for content that matches at least a portion of the indication of the topic of interest; and identifying a piece of content as being relevant to the topic of interest based on results of comparing the indication of the topic of interest to the multiple pieces of content accessed from the computer memory storage system includes identifying a piece of content as being relevant to the topic of interest based on results of searching the index for content that matches at least a portion of the indication of the topic of interest. 10. The method of claim 9 wherein: accessing, from the computer memory storage system, an index of multiple pieces of content includes accessing, from the computer memory storage system, an index of topics of the multiple pieces of content; searching the index for content that matches at least a portion of the indication of the topic of interest includes searching the index of topics of the multiple pieces of content for topics that match the indication of the topic of interest; and identifying a piece of content as being relevant to the topic of interest based on results of searching the index for content that matches at least a portion of the indication of the topic of interest includes identifying a piece of content as being relevant to the topic of interest based on results of searching the index of topics of the multiple pieces of content for topics that match the indication of the topic of interest.