I've been riding single speed for quite a while now. This is mainly by default, caused by the decay of the bike I was riding. For too long now, I've been riding my Dad's old bike, which was meant to be just an interim solution. In an attempt to prolong its life, I removed the derailleurs a long time ago, lined the chain up as best as possible and rode (poor man's) single speed.
Recently the freewheel has been playing up, but opposite to making the bike fixed: instead the freewheel would choose to be disengaged most of the time, so once it was engaged I choose to keep pedaling as much as I could (because having it disengage on the way into roundabouts is very scary).
So I've kind of been preparing myself for Fixie. And waiting for our Cycle2Work scheme to start.
Watching fixie riding scares the shit out of me. It makes me feel really uncomfortable. But I can make a comparison to skateboarding there (or any such activity, surfing, snowboarding, etc): You can be a fixed gear rider and not have to try and kill yourself everyday. It's a pro vs amateur thing. I'd much prefer to keep myself at the bottom end of the amateur bracket, enjoy what I'm doing and push my envelope rather than someone else's. No need for jumping off buildings.
Brakes are fine. You can just slow down if it's getting a bit nary. If the utter worse comes to the worse you can kick your feet off the pedals (I rate those who insist on clips or SPDs with Fixie in the Mental-Pro category. I'm not going anywhere near that) and pull on your brakes to stop and start again.
I'm also not going to learn skip stops. Mainly because I can't afford the tyres. Skids were great fun as a kid when your dad was buying new tyres. Not so much now.
Going up hills isn't too hard. You can't freewheel, no, but you can ease off every few revolutions to give your legs a break. You don't have to be pushing it hard all the time.
And it really is ok to put your feet down. You won't have your bike confiscated. I'm not doing any of that trackstand bollocks. And I'm especially not going to practice in the living room.
Mounting and dismounting: A lot seems to be made of getting on and getting off a fixed gear. All you have to do is get on and get off. Don't worry or think it too much. It is still just a bike!
So when it comes down to it, you can ride fixie without having to go to extremes. No matter what anyone else says. There'll always be someone more extreme round the corner. At the moment you're 'not' a fixie rider if you "use brakes", or don't have "clips or straps", next week it'll be not a real fixie rider unless you "have a wild boar strapped to naked back". If your bike is fixed gear, you are riding fixie.
After a weekend of riding Fixie for the first time ever (unless you count the first trike I probably had as a toddler), it's really not that scary once you are doing it. In theory it should be easier to remember to peddle all the time, but to start with it is difficult not freewheeling at certain times (going down hill, over bumps and potholes, turning right into a junction), but as long as you have brakes, you're sat down and your feet aren't strapped in you'll be fine. And after the scare, next time you'll remember to keep pedalling.
And you should try fixie if you can, not because of the image or attitude or culture that goes with it, just because it's fun.
EDIT: The biggest danger so far is off the bike: Walking with the bike, forgetting the pedals will spin round and having one whack my shin.