I'm always selling Amazon giftcards on demand for a little better than current market prices, in any amount (well, up to a certain limit I guess).
how is yours better than Spendbitcoins.com ?
never used spendbitcoins.com before, but you can negotiate with me and I pretty much just do US amazon gift cards. I can work out other stuff as well for other amazon purchases or non-US amazon sites, but it might not be a better-than-market rate. I get a slight discount on US amazon purchases, plus it means I don't have to wait for dwolla/mtgox and I can put it on my credit card for the time being, so I usually will take offers for slightly better than market rate (~3% better) for giftcards. I'm also not a retailer or anything, just putting a bit of money into bitcoins...