the majority of phrag species and most of the hybrids will appreciate sitting in water to maximize their potential, but that is not a requirement if you can water them enough. in nature they grow in tufts of grasses or mosses near riverbanks & waterfalls, so the roots are always wet and prone to flooding as well.

most phrags appreciate high light levels--some will thrive growing side by side with standard catts (except with much more water, of course). most of them will also tolerate lower light, although their leaves are larger under low light conditions and they may bloom once a year instead of twice or three times.

some of the besseae hybrids are very compact, with leafspans in the 10-15" range and spikes no more than 1-1.5 feet tall.

some representative phrags at:
http://homepages.nyu.edu/~jlc314/