Walkabout and hotels in the area
I've only eaten there once - as per the previous poster, I can't recommend it. However the beer is cheap and the atmosphere laid back. It's a fairly relaxing place to hang out 24/7. Security seems pretty good. You have to be picky with the rooms as they vary enormously. (Why would they give you the best one if you just accept what they give you?) Always ask to see a room before you pay - it goes for almost anywhere if you get the chance, unless you feel a psychological need to book ahead. The first room they showed me was awful. The second one quite acceptable. (And it's cheap). I didn't find out about the luxury rooms on the rooftop till I had explored thoroughly. The worst bit about walkabout was maybe the attitude of some of the gringos. They varied from (what I'd call) normal, to completely green, to looking like a leftover from the Vietnam-US war (as if they'd just gone awol and lived in walkabout ever since).
For something more upmarket, go a block and a half towards the river and you'll find an exquisite French owned, French run place with very good food, a bar that sparkles like you can see your face reflected in the polished glass, and staff and owners that have a real sense of class (in the good sense). If you speak good French you will probably become friends for life. But you do have to cross the main road.
Nearer walkabout there's a cheap-as-catnip place almost opposite which is Vietnamese run. Many of the rooms are very spacious, quite awesome value for money. Downside is if the owner couple have a domestic that leaves a bit of an atmosphere.
The Flamingo sucks IMHO but that is mostly cos it's not to my taste. Rooms I looked at were tiny, cramped and soulless. The whole place is like a bit of a cheap army camp hotel, trying to be a bit upmarket and failing miserably to spend enough money. But there again it is maybe the closest thing you'll find to a westernised (American-friendly) hotel in the area at a cheap price. You can recognise the things you'd look for back home at a cheap backstreet hotel which just about ticks the boxes (and quite ostentatiously so).
There's many in the area. No harm in shopping around. There's also many good places to eat. No now need to eat typhoid trap meals.
I think anyone knows that Phnom Penh is not exactly for beginners. You have to grasp the local realities quickly but also have a strong sense of who you are, how to be civilised and decent in a country that lacks civilisation (in terms of the person you are - not in the sense of demanding hot water and western efficiency). But you are not as invisible as it might at first seem. So do please show the world - fellow ISGs, NGOs, and the long-suffering Cambodians, that you have certain standards. We might be mongers, but by playing fair we can earn everyone's respect. There's a lot of good decent people in the country. I think like attracts like.