Laptop is running Ubuntu Lucid Lynx 10.04 exclusively. My desktop PC is "out of commission" until I buy a new one and build it from scratch.* PC was running Windows 7 Ultimate with Lucid via Wubi. Was planning to transfer the filesystem and replace the Windows partition with it, but that's another reason I had to decommission it.
So yeah, Linux exclusively on laptop with WinXP via VirtualBox for my work at the Salvation Army. People are using Win7 there and were testing out alternate server methods using a combination of Ubuntu Server with TurnKey Linux Domain Controller and WinXP Home running on the server using headless VBox so it can handle being an image scanner server...don't ask...
* - Motherboard is causing major crashes and stalls in both Windows and Linux, so I knew it was a hardware issue and all individual parts were tested. Motherboard has run its course.
Ubuntu, Fedora, Gentoo.
Ubuntu, XP.
Embedded linux (NAS).
That's at the moment - was running openSUSE, Sabayon, Puppy and jokingly Mer previously.
--------------
@paai
As far as calendars, have you considered just using Google Calendar? Alternatively, Thunderbird+Lightning (or digging up Sunbird) should work in EasyDebian chroot.
1. Ubuntu 10.04.1 x86 on the laptop, but I'm going to switch to Fedora 13 x86 today
2. Debian 5.0.6 x86 on my old desktop
3. Arch Linux x64 on my current desktop
4. FreeBSD 8.1 x64 on my current desktop
5. Windows XP SP3 on my current desktop
6. Windows 7 x64 on my current desktop
And so I run quadruple boot on my desktop :P
Forced to use it. But also have ubuntu 10.04 x64 on 2nd and 3nd partitions.