I want to get a US sim card for one of my spare tri-band phones so I have a local number when I'm in the States. Any idea where can I get one of these from?

Search on eBay for "T-Mobile SIM".

I agree, 100's of them on ebay...

Expansys USA used to sell them, but I don't see them on the site anymore...

Wow! Why are the cards now so cheap? they are selling, Buy it now for like 5.00 with a 5.00 shipping charge and 125 minutes on them?

that is about 25$ less than before, or more?

any thoughts, are they switching to a 64 kb sim or something?

that is a smokin deal now. Almost better than with t-mobile directly

There was something on HoFo not too long ago about this, it all comes down to that the dealer doesn't pay much (or anything) to convert it to a prepaid sim, they usually sell a sim out of their own inventory and T-mo adds some call credit by default, it was also said that the ones with "$80" of credit on them are not really $80 worth, but need some creative calculating to reach that amount.

looked into this in detail on my recent US trip. ebay is one option but another is just to buy a prepaid us mobile (virgin are cheapest but others also offer) from a store (addresses on the network web sites) or over the internet (can be cheaper - in which case deliver to a hotel or other address for your first night of stay). chuck away the phone or sell on ebay if you dont need it. however you need to check whether the network you are buying covers the area you are in (pretty similar for main metro areas but differ considerably outside), and also whether non-local calls are charged at higher rate (every us mobile comes with a local no, unlike say UK)

The cheapo sims (~ $9-12 total) have their value expire in 10-30 days after ebay purchase. Unused balance can be kept if the account has additional credit applied before the (short) expiration date.

Most Novembers and Decembers, T-Mobile sells 12 month expiration sims for the holidays.

I just bought one with 224 minutes and a December expiration date for US$40 total. The pricing on those runs from US$35-50 total.

My T-mobile deal is a fine one that works well for my current low usage situation.

BTW, the cheapo (120 minute) sims at the official T-Mobile shop that I visited went for US$54. And the sales clerk at that shop couldn't immagine how anyone could sell it for less!

Oh, yes. There are many, many places in the US that T-Moble has no service. Consult their service map before buying anything from them.

I would definitely check street level coverage before purchasing a T-Mobile pre-paid SIM card. Cingular/AT&T wireless has better coverage, and their pay-as-you-go plans are about the same as T-Mobile. Those are the only two National GSM carriers. Otheres, like Verizon and Sprint also offer Pay-As-You-Go I believe, but they use CDMA and TDMA, so you will not be able to use your own GSM Handset.