Just installed Lucid on an old base unit this weekend, having previously used live editions of Ubuntu before. I rather like it. Nice clean interface, a few irritations like window resizing and close buttons being on the left rather than the right (fixed that straight away), and I haven't used a tenth of the installed gubbins as yet, but it hasn't fallen over yet, though I did get some backup software installed pretty quickly just in case.
In the process of working out how to move a copy of my Thunderbird email accounts from an Xp pc to the Ubuntu one. Anyone done this recently? I suppose I could manually re-enter the 5 sets of account details and configure them one at a time, but I'd rather not!