E-mail is very handy for keeping in contact with other librarians and other libraries. I use it on a daily basis to get information from headquarters and also to respond to requests. I like it much better than a jangling phone, because I can answer the requests on my time. The communication of a written request is also something that I can remember better than a voice one. I can print up a copy. I can also think and plan my responses more carefully.
I'm not sure about the other 2.0 tools. I signed up for Yahoo messenger, but I have no one to talk to--I contacted Sharon in Milaca, but she hasn't reached that number of the 23 items. I don't have a cell phone, so I can't use IM. I listened to an archived Minitex podcast about deli.ci.ous, but in 11 minutes I was interrupted several times. I never did get the whole thing watched and I couldn't pause it. Many of the other podcasts are 40 to 50 minutes. That kind of time without interruptions is not possible in a small library like mine.