We don't regularly feature mobile apps, but we're very taken with the Christie's iPad app.
If you've got an iPad, you can auction away like you're there. Well, almost. For a start, you can view a selection of lots from upcoming sales in large format, view past results, email lots to friends, find out how top buy and sell as well as being able to leave absentee bids for items that catch your eye. There's also full-screen videos of upcoming sale highlights and gallery talks, plus directions to salerooms across the globe using Google maps.
Downside? As yet you can't 'live bid', but we suspect that's coming. If you have an iPad, grab it now for free. Christie's on iPad