Where do you get SIM Cards in the USA?

I went to Europe for the summer and needed a cellphone so I dished out $150EU for a Sony Ericsson W200i, I bought it at a Best Buy type store it was unlocked so I was able to put in any SIM card I wanted so I just picked one up at a gas station for $17EU and used prepaid phone card to recharge the SIM card, but now I brought it back to California with me, Its a tri-band phone but it should work fine here as long as I can find a provider that will hook me up with just a SIM card.





So does anyone know what the best option would be, is it even worth it?





Please help, Thanks

Where do you get SIM Cards in the USA?
If you want to get hooked up with JUST a sim card (AKA prepaid service), then theres really only 2 providers.





Cingular/AT%26amp;T offers the GoPhone service. Just walk into any AT%26amp;T store and ask to get a prepaid SIM card.


T-Mobile to Go is the other option.





Personally, I prefer GoPhone. They have good connectivity all around. Although GoPhone is a little more expensive than T-mo to go, it's worth it. When I called customer support the first time, I was hooked up with a representative within 30 seconds. T-mo made me wait about 5 on average.





T-mobile's SIM card failed on me and I tried calling support 4 times and they never helped. I went to the store to ask for an exchange or to have THEM test the SIM card, but I got yelled at.
Reply:go to any gsm store and ask for a sim card. they cost around $20.