Sometimes that's easier said than done. (remember -- I already mentioned security clearances taking months)
Imagine working at a place that has a restriction on the use of IM. They finally lifted the restriction for Jabber/SSL. We started using it for a couple of months, but then they changed the policy, and we had to file paperwork. So I did. A month or two later, I got permission to use it, specifically for the project I was working on. Then I was informed that I wasn't allowed to use a public Jabber server. So one of the folks on the project installed it. Another month or so later, the security folks called to get the IP address of the server. I told them, and they freaked out that it wasn't at our site. So I suddenly had to install Jabberd locally -- and I spent 2 weeks trying to get something working under MacOS 10.3 (which didn't have Java 1.5) with absolutely no luck (this was the point when the jabberd2 servers got hacked so many resources were unavailable). Finally, my boss got me developer access so I could install MacOS Server 10.4 beta on one of my machines (which came with jabberd).
So yes, with IM, I can get a 10-30 min turn around on discussions as opposed to the 2 days that it took via e-mail. (and maybe 2 hrs using a mix of email and phone), but I've probably lost a month worth of man-hours in getting to the point where we can use it on this project. With 4 of us on the project, we've easily made the time up, but it's frustrating.
Oh ... it was bad enough that at one point, we were using various 'talk' varients