[Web4lib] Social networking sites

[Judy McBrian]

At the risk of starting a long discussion on the merits, or lack thereof....
Our small library has had an ongoing problem of young people taking up 
all the
available computers for social networking sites like MySpace, and has 
decided,
as an experiment, to block these sites from a small group of computers 
using our
CIPA related filtering software (Yep, we get money from the feds for
our T1)
Our main objective is to free up 4 pc's for other use, leaving the 
majority (10) free
for those popular sites.
While I'm familiar with MySpace and Facebook I know there are other
popular sites (I don't need a "comprehensive" list) I can't seem
to recall the one or two others I will need to "block"  
A little help please, from the knowledgeable will be much appreciated.

Thank you
Judy McBrian.