I am planning on riding at least one century a month this year. I may even try to get a 1,000 mile month or two in too.
Last Sunday, I did my first for '08. Where our group ride normally starts is 22.5 miles away from home, so I rode in, then rode the 44 mile group ride, and another 22.5 home. I was so close to 100 miles that I rode around where I live to get the remaining miles in.
All in all 100.3 miles in. Started at 7:15 in the morning and finished at 3:27 PM with various stops (waiting for the group ride to start, rest breaks, etc.).
The group ride was actually in memorial of a great cyclist that passed away New Years Eve. I kinda felt it fitting to get 100 miles in because he was an avid cyclist who rode many centuries and had completed a 10,000 miles year in 2007. I only knew him from one conversation prior to a ride, but from all I've heard from those that knew him, he was a GREAT guy with a HUGE heart!