Very good article. Just to add my 2 euro cents, I bought in a brick and mortar photography shop an OM->
adapter this week-end. The brand is 'kipon' and the seller (a competent guy, whom I bought my e-p1 from 1 year ago) told me kipon was the chinese manufacturer of novoflex, and that basically they were the same adapters but with a tad less Q&A on the cheaper kipon brand. This from a shop that caters mostly to pros and don't even stock
cameras because they're a bit on the toy side for their standing - but they'll happily take orders and don't apply an over the top margin on the wholesale price.
I paid circa 80 € (with a 'no question asked' return policy in case something would be wrong), but I have to say the fit is perfect at both ends, and the springs on the OM side of the mount are true springs and not a cheap cut'n'bend of the prongs.
All in all, I'm very pleased of the results so far. I know there are many adapters to snatch for half the price on the 'bay, but 40 € is a decent price for complete peace of the mind.
ps : first test of a silvernose OM 50 mm f/1.8 (already posted on the 'show people' discussion) :