30 Xterms doing everything from Updates to compiling to watching logs, 2 Firefox sessions with multiple tabs per, Evolution, GIMP, Inkscape a music player, VMware with Windows inside that only the Office suite or Our Mailing suite running, maybe a firefox sessions as well.
That machine runs a backup DNS server and a failover DHCP, as well as stock CUPS CLient, Xserver, etc... Sometimes I even use the Console (running at 1024x768 with 50 lines) to do some more taxing work instead of X.
Mind you this machine is a 1.4GHz AMD 266FSB with 1.5GB of Memory (PC133 at that) and only when I am chugging along on an "apt-get dist-upgrade" on the machine, do I really feel it.
All this on a 17" Monitor, for now. Still trying to get a Dual G5. Which I'd get a Flatscreen 21" for. When I get that, I WILL dual boot it. Both MAC-OSX and Linux. I just WILL NOT do without Linux. Yes, Fink is nice. But I like my X Configs done the way I want'em.
I typically have 4 Desktops, One for General, one for Admin tasks, one for programs I have open but don't want in my way for now and one for E-Mail and Browsing. All 4 have the IM stuff in it.