I know there are still some of us out there; the old school Ultima Online veterans, one of my favorite gaming experiences ever. Probably still my favorite MMO ever.
A couple months ago something reignited my interest in the game and I went out just looking at info about where the game was at etc. I messed with the official demo and didn't like it as it didn't sync up with my memories of the game (as nostalgia is want to do it blurred my vision of whatever the current game is).
I found in my searching that there is a pretty vibrant community of player run servers out there for almost all the time frames of the game. For me my best times were the end of the vanilla game and into the Second Age expansion. I happened to also find a server that was just getting launched and offering a fresh start, as a player that was getting fresh back in it seemed like a good deal.
The server has been live for a couple weeks now and is off to a great start. It is well maintained and has had almost perfect uptime; the admin is active and has been very receptive to the player feedback on tweaking small things (loot tables, vendor prices etc).
If you are interested or ever had an interest in Ultima Online and want to get a taste of what it was like (in what I consider to be the best time period of the game) check out http://www.uoimmortalis.com/
and log on. Free to play and the D/L of the client shouldn't take more than a couple hours. You will find people on the forums and in game willing and able to help newcomers.