I had the same question when considering a belt drive bike. I found a video that demonstrates exactly how it's done with a Spot Brand bike, so I thought I would add it to this old thread so future searchers can see it: acme-ajax tech 720p on Vimeo

I ended up buying a Spot Acme. They are well designed for belt drive. The only thing I needed was a 15mm wrench multitool to get the back wheel off when out on the road. One of several fixie tools will do the job (Topeak Urban 8 or Nutter tools are great).

The one thing I would recommend confirming before buying a bike is whether re-tensioning is required when removing the wheel. The Spots don't need it, but some others do - and that requires more tools and complexity. According to joe-bike.com, the Raleigh Cadent requires re-tensioning.