If you have the time, a half day - preferably the afternoon - spent cycling around here is very well warranted.
You can rent bicycles on the island, or you can take one across from Kratie on the small boats that run back and forth between the two. The ferry costs 1,000 riel per person (bikes are free). Bicycles can be hired on the island for $1 and a small restaurant does basic staples, plus a couple of drink stalls near the ferry landing will keep your thirst quenched.
Once you're on the island, you can follow the bumpy nine-kilometre trail that encircles it. The trail is beautiful -- if you're looking for a single opportunity to take in rural Cambodia at its most beautiful, this should be towards the top of your shortlist. The scenery is lush, and unspoilt, with a few villages, grazing cows, and smiling kids around the perimeter and fluorescent rice paddies in the centre.
Among other points of interest, there is a temple at the southern tip, a floating Vietnamese village to the southwest and a newer temple and ancient chedi near the centre.
You can watch the sunset from the island's western banks, but be sure to arrange transport back ahead of time since the last scheduled ferry leaves promptly at 18:30 -- swimming back is not recommended -- especially if you have a bicycle with you.
Several NGOs organise home stays in some of the villages as well as in Koh Trong -- they can be contacted through their web sites if you plan ahead, and CRDT has a kiosk on the grounds of La Bungalow in Kratie town.
Cambodian Rural Development Team: (023) 357 230; www.crdt.org.kh; No. 695 Street 2, Kratie
Cambodia Community Development: (012) 674 800; info @ crdt.org.kh (for island homestays).