I'm planning to get a camera for my commute and for the odd bit of filming on MTB and with the family. I don't really want to mount it to the top of my head, partly because I'm always bashing my helmet light (tall and bad at ducking) so would constantly hit things with it, and partly because it looks a bit rediculous.
I'm keen to get a gopro as it will do loop recording. Has anyone successfully mounted one fairly close on the side of a regular bike helmet, and if so, how?
Mounted mine on the side: you'll need a couple of different brackets to shift the orientation. On an XC lid you'll need the vented strap. Trouble with on the side position is its quite a weight and has a tendency to pull helmet down. It's not stealth, you'll look just as ridiculous as if it's on top. I used to run a vio HD bullet cam and it was easier to helmet mount but the go-pro has the chest mount which is why I swapped.
Don't have a GoPro, but have tried mounting my small Tachyon camera on the side of the helmet and even though it doesn't weigh much it did make the helmet keep twisting down on that side so it's ended up back on top. Mind, it doesn't stick up as much as a GoPro but it does still get caught on overhanging branches once in a while.
Your best bet might well be the chest mount, so long as you don't need to always film whatever your head is pointed at.
I think I'd use the chest mount for mtb, but I guess I'll have to live with it on the top for commuting, where I really want POV. It is a bit off putting though as I'll look even more of a dick than usual.
Bear in mind while the new GoPro does loop recording, battery life is only a couple of hours max so battery generally goes before the memory card is full anyway.