Canadia Bank
Not to be confused with canada, this bank is wholly cambodian owned. this particular branch doesn't take baht, and exchanges money at a slightly poorer rate approximately 4,000 riel to the usd than you'll get at your guesthouse or on the street. they will cash traveller cheques and offer free advances on mastercards. best to avoid this one unless you need to replenish your supply of american cash while you're in town.
Acleda Bank
31-33, ph khemarak phomin also has an atm but doesn't yet accept international cards. they can change dollars and thai baht only but they accept traveller cheques. western union services are also available.
Kampong Cham features a few markets, but the best is the one the locals use. It features all sorts of food, ranging from standard mangoes and other fruits, to pig heads and live fish. As with all other food places in the area, use common sense when buying here, as there are health hazards to the unsuspecting Westerner. It's just down the road from the Mekong Crossing restaurant, but stalls only open during daylight hours. Some food and juice stalls stay open until late, i.e. 9 pm.
Cambodia Public Bank
5-7, ph angduong, coming from the bridge turn right at the roundabout from where it is about 200 m exchange money and has an atm accepting visa, mastercard and maestro. this is the last atm when heading north until pakse in lao.
Internet cafes
There are a couple of internet cafes around town, especially on ang duong street between the market and the bridge over the mekong. the going rate is 2,500 riel per hour.
Money changers
Are available throughout the city, particularly in and around the markets - look out for packets of money on display. they will give you a slightly better rate than the banks but you have to ask around for the best deal. some of them do also change other currencies than dollars such as thai baht and vietnamese dong. occasionally, other western currencies are changed as well but expect a poor rate. it is not possible to change lao kip.