Another passion of mine, it's really part of the triathlon gig, is cycling. Here's some of my favorite cycling activities that are not associated with triathlon.
Follow the Tour de France: Even before Lance, I was a TDF junkie (remember Greg LeMond?). Someday I'm going to watch the race on French soil. For most of July, the best professional cyclists ride approximately 2000 miles, mainly through the French countryside and mountains. You can follow the progress of the race on http://www.velonews.com/ or the official TDF website http://www.letour.fr/2010/TDF/COURSE/us/index.html.
In April 2005 and 2006, I rode 170-180 miles from Houston to Austin - the MS150 ride to support the National MS Society. A wonderful experience that I recommend highly (http://www.ms150.org).
While living in Seattle from June - Dec, 2009, I rode the Cascade Bicycle Club Seattle to Portland (STP), 200 miles in two days in July. Some crazy people do that in one day! (http://www.cascade.org/EandR/stp/index.cfm).
Closer to home, hook up with the Brazos Valley Cyclists. During the summer months they sponsor a weekly time trial race to test your cycling fitness and really get your heart rate maxed out (http://www.brazoscyclists.org/).
A great group of students, mainly from UT, have organized a ride from Austin to Anchorage, Alaska (70 days; 4500 miles!) in order to support the American Cancer Society. Follow their progress at http://www.texas4000.org/. In early June they sponsor a 70-mile ride from Austin to Lampasas during which you could accompany the Anchorage-bound riders on the first day of their trip. It was a great ride; highly recommended!