Recently Twitter announced a major new feature soon to launch: the ability to create sharable lists of users around topics of interest. There comes TwitWho.net works as a twitter directory, allows you to create a variety of groups of friends, colleagues.You can also become a moderator for TwitWho.net. If you have more then 999 followers and more then 99 tweets you can apply.
TwitWho is a twitter based service that provide directory like view on twitter users.
There are 2 main use cases:
*to find experts in some field, celebrities, news channels, etc..
*to create custom group that includes just your friends, colleagues or family members.