Member-created review site Lunch is launching what could shape up to be a nice solution to this problem with "Twitter Lists," a way for users to create their own lists of Twitterers in particular areas or topics and include editorial content about what makes them follow-worthy.
Think of it also as a more elegant way of handling Follow Friday -- instead of a string of woefully incomplete @usernames because you couldn't fit everyone in, just send a link to one of your Twitter Lists.
We wrote recently about TweepML which similarly provides the ability to group up Twitter users into contained lists as well (you can follow the Mashable team here). Lunch's implementation lacks the ability to one-click subscribe to a whole list at once, but adds some other nice functionality and has an arguably more user-friendly user interface.
For one thing, you can easily import your entire Twitter following list to kickstart your process. Then you can sort and select from the list, order it, add individual comments about members of the list, and share it out on Facebook, Twitter, by email and more. You can even send out an @reply to the people on your list to let them know they were included.
Integration with the Lunch site adds further features to the lists by tapping into its Similarity Network to help put the creator of each list into context. Based on your own profile you can see how relevant the list creator is to you via the engine's calculation of your shared interests and opinions.