been using skype for ~16 months, use web and im, too (of course)... love it and strongly encourage my clients to use it, too. no sense in paying for stuff if you don't have to. some other great freebies:
* blogger (obvious)
* jotspot (free, limited use wiki - up and running in <3 minutes)
* openoffice.org (open source msft office equivelant)
good stuff, wouldn't be without them.