As I've mentioned, I've been in the Mesa/Tempe area for most of the summer. I have to say I was pleasantly surprising with biking there. I always thought of Phoenix as being like Houston - a city that grew up in the car age and therefore is not very bike friendly, but if I'd read the League of American Bicyclists list of bicycle friendly communities I would've known better. Chandler, Gilbert and Mesa are all Bronze. Tempe and Scottsdale are Silver. And once I was there it wasn't hard to see why. There are bike lanes everywhere. In fact the area has some real solid advantages over D.C., some natural some not. For one it's flat. You can get by in one gear the whole time. The roads are straight and there's a pretty solid grid going at all times. Because there's no street-side parking there is almost no door zone, so the bike lanes feel wider than the ones in D.C. In most places where there aren't official bike lanes there is several feet of shoulder - in some places they would call that a bike lane, but in Arizona they seem unwilling to label something a bike lane if it's less than 4 feet wide. And those shoulders are effectively wider than D.C. bike lanes because there are no parked cars to your right.
There are other facilities as well. Bike racks on buses, bike rest areas, and parking in a lot of places. In fact, out there they often use inverted U's as bollards. There are a few trails, but they usually aren't very long or very nice. The nicest runs the length of Scottsdale, but it would barely crack the top five in the D.C. area in my opinion. Part of the problem is a lack of trees. Tempe town lake has trails along it that are nice too.
There's a system of canals through the region (we would call them ditches in S.E. Texas) and along them dirt or paved access roads for maintenance crews. The Maricopa County bike maps shows many of these as bike routes, but often you have to negotiate locked gates, dirt roads, poor grade crossings and full sun as there are no trees along these. They've got potential but they haven't tapped it yet. In a few places there are legitimate trails and these are nicer.
One thing that struck me is how many trails go right by a golf course without any protection (Arizona is about 45% golf course so it's pretty inescapable). I note this because Langston Golf Course won't allow the Anacostia Trail through it's property because they believe it isn't possible to do it safely - despite the fact that the Paint Branch Trail and the Capital Crescent Trail both seem to manage it.
Despite all this, I haven't seen that many other cyclists out. Kids. Some guys pushing tricycles selling burritos and hot dogs. The occasional other commuter. Of course it is 110 degrees out, and I don't ride downtown, but I think more of it is that despite how easy it is to get around, everything is farther away. The area is not built to a human scale. The grocery store is 3 miles away. The mall is 3 miles away. The bars are 10-20 miles away. Nothing killer, but certainly not as easy to deal with as D.C. And the roads are ugly. It's just you on a sea of asphalt riding along side parking lots and gas stations. There are the occasional downtowns - like Tempe, Phoenix, Mesa, old town Gilbert but these are the exceptions. The sunsets are fantastic though (and due to the heat and my lack of lighting, that's when I do most of my riding)
I find that I like to ride along the roads where the light rail is being built. (Each light rail car will have racks for up to 8 bikes) The pavement is fresh and the cars are still scared away so I often have a whole two lane road (with a bike lane) to myself. Plus it's fun to look at the construction. And now pictures:
An usually narrow bike lane and in the gutter - also not normal.
Here is one of the access roads along the canals
The inverted U bollards
The trail along Tempe Town Lake
A bike rest area. These are nice, but I've never seen one used.
A statue in downtown Mesa
Decorative bike racks in Downtown Mesa