Follow Friday is an opportunity for people on Twitter to reccomend who to follow. You simply tweet out the names of the people you want to recommend and tag it with #followfriday so that it shows up in Twitter's search. #followfriday always becomes a trending topic.
The problem is however, you only have 140 characters to work with, less because you have to put the #followfriday tag. So that limits the number of people you can recommend in one tweet. People often clutter up their timeline with several tweets of the people they recommend. For people who are reading the tweets, they need to laborioulsy click on each recommended person individually and read through their timeline.
Mixtweet offers the perfect solution. Create a list of the people you recommend and then link to it. Done. No limits to the number of people on your list and you can add to it each week or create a new list for each followfriday. Plus everyone can see all the updates for the people you recommend in one place, live. For example, here's @therealcherilyn's Follow Friday list:
Can you imagine how many tweets it would take to recommend this list of people?!