Bullionvault.com is a bit like goldmoney.com; they offer online gold and silver. But Goldmoney is a digital currency as well as a means of storing metal, while Bullionvault is just storage. You buy and sell directly with other users in Bullionvault, in a bid/ask spread interface which is reminiscent of Betfair.
Bullionvault is located in the UK, while GM is in Jersey. The people who run Bullionvault are members of the LBMA, which in this fun new world of ours is both a good thing and a very bad thing.
Personally, because Goldmoney are offshore and not associated with the LBMA, if I had to choose I'd go with GM, but BV are an ok choice. Both are well established and hold something like a billion in metal.
Long interview with the founder of BullionVault, worth a listen, good story at the end about an old Portuguese gentleman.
Recording and transcript: