If you're like me, the biggest limiter on how often you race might be your wallet rather then ability. I'd love to do a race every few weeks, but can't justify the fees, especially since most of them would be glorified training days.
For those Canadians out there, MEC is now doing races! Cheap registration, at $10 for the 5K and 10K distances in Calgary. I've signed up for the 5K on April 21. Time to update my personal best on that distance!