My fiance has just started using this service and it's pretty good, they'll even hold packages so you can buy several items over a period of time and then have them mailed together (may be good for group buys

). Recent example - I've just paid US$100 to post some driving lights from the US, then I got stung by customs

for a further AU$100 , using shopthestates we had another parcel sent which was twice the size and weight however it only cost US$54 and no customs nonsense (apparently Fedex, DHL and UPS always declare goods, whereas normal priority airmail often escapes

).
Furthermore if the supplier/shop insists that the purchase must be made using a US credit card I believe they offer a service where you can use their credit card number and then they charge the amount to your account (pay via Paypal)- something else I wish I'd known when I bought my driving lights.
You live and learn - although I struggle with the latter.