It depends upon what you mean by 'live'.
Graeme74 seems to have assumed that you mean eBay's normal online auctions (rather than 'Buy it Now' items). If so, Graeme74's answer is correct except that (to get rid of 'Buy it Now') you should also check the 'Auction' box, under 'Format', down the left hand side.
However if you're referring to eBay's entry into the world of 'real' auctions (i.e. in physical auction houses, with auctioneers taking bids) it seems that it's currently only available via eBay's US website:
http://pages.ebay.com/live-auctions/about.html