My main character - see signature for the Story Hour - Lucifus Cray the Alienist took leadership for a couple of reasons:
1) He has Tunthi the Half-Orc (cohort) following him around (good comedy value if for no other reason).
2) He has a very large number of young women (followers) who comprise his harem.
3) He has a handful of like minded experts in the field of Arcana and the Planes forming his cult - The Diabolerie Arcane.
4) He now also has a Dwarven librarian (follower) who he can trust not to sell anything he's not supposed to (Lucifus travels around in his portable tower selling books and other strange arcane devices). However, the librarian is so dull, he could almost be described as eccentric.
High level combined with good charisma and a certain level of notoriety means that his leadership score is pretty good. However, I let Paul the Wunder DM worry about the numbers. I just give him the personalities of each follower and cohort.
As you can guess the majority of this is for flavour although sometimes it helps in terms of information. Followers are fun but would be down right annoying if you had to cart them around everywhere.
Anyway, if you are interested by this unusual use of followers, follow the link below.
Best Regards
Herremann the Wise