Before my last major upgrade (2.0 to 2.3… I think) updating was always a long process involving multiple diffs, backups, manually merging my plugins and changed files, etc. Not any more…
What changed? I decided to use the instructions in the codex to convert to an svn-based installation. This process might look a bit arcane, but the benefits are outstanding. This time, my update only required two steps:
svn switch http://svn.automattic.com/wordpress/tags/2.3.2/- Visit the upgrade page under wp-admin/upgrade.php (which didn’t actually do anything this time around)
There are some caveats (disable plugins and test on a development site before a major upgrade, take backups, cross your toes, etc) but all of the grunt work has been removed. I whole-heartedly recommend this process to anyone who isn’t scared off by the command line.
-J
P.S. Happy New Years, Merry Christmas (belated), etc to all. I like this time of year, it makes my sporadic blogging seem more normal 
1Leszek Pawlowicz on Dec 30, 2007 at 10:27 am:
Have you tried the “Instant Upgrade” plugin?
http://www.zirona.com/software/wordpress-instant-upgrade
It’s always worked for me - click a button, and you’re donel
2Jason Birch on Dec 30, 2007 at 1:50 pm:
No, hadn’t seen that before. In general, I’ve been trying to reduce the number of plugins I use, since this is definitely not something I want to spend a lot of time managing.
Also, I’m a bit of a geek, and feel much more comfortable knowing what’s going on during the upgrades…
3Ivan Milicevic on Dec 31, 2007 at 5:19 am:
Happy hollyday’s to U2 Jason”
4Tom Kralidis on Feb 5, 2008 at 7:38 am:
Great recommendation! I thought of this post as 2.3.3 came out today — very easy.