The options are many, and people make use of the Internet everywhere.
Most hotels have computers in the lobby for guest use as well as wireless. The speeds we've encountered are not great (typically 1-2mbps down; 0.15-0.6mbps up; 20-60ms ping) but sufficient for most needs.
Internet cafés are easy to find, and exist in more than just cafés: here in Bang Bao on Koh Chang island, a scuba shop on the pier has 8 terminals and charges 1 bhat/minute (~C$2/hr).
It isn’t a big surprise that mobile phones and wireless Internet is the norm though. Wiring is a nightmare, with no apparent rules for how to connect to the grid. Some posts have so much wire hanging on them that you need to duck to pass under them!
