I use twitter for staying social ofcourse.. I stay in touch with my friends all the time. I can share videos, photos etc.
I have several twitter accounts, private and business. I use them for marketing purposes as well as following interesting people to get relevant news fast (tech evangelists, etc)
it's a social networking and micro blogging tools, now people misuse as a link-tweeting.. and i do not like it very much anymore.. it's a bit overrated and even twitter itself doesn't have a business plan.. besides the fact that they are well-known and successful, one big drawback is twitter actually is kinda one way direction.. which is good but not effective if you are into real social networking.. just my 2 cents
i use twitter to know what my friends and families are doing. then also get updates from celebrities. promote site