Barence writes: Invites to join the Google Wave beta are changing hands for more than Â£50 on eBay. Invites for the service — which rolls together email, instant messaging and micro-blogging — were released to 100,000 pre-release testers last Wednesday, each of whom could invite five more people to try out the service. Invites started turning up on eBay.co.uk almost immediately. On the first day, 34 invites were sold for an average of just under Â£25 each. The most expensive went for Â£55; the cheapest for only Â£9.44 via an American seller.