Today, I went to Letchworth for a nice long bike ride. In the morning, I did 28 caches, and another 30 in the afternoon, although there were a fair few DNFs. Late in the afternoon, it rain quite heavily, so I got a bit wet. But that's all part of the fun, and at least it wasn't cold wet rain.
It seems to me that you don't need a GPS to geocache in Letchworth. Just look behind every green BT box and you'll find a cache.