I'm in Australia. Originally I planned to switch from Telstra (AT&T frequency) to Optus (T-mobile frequency) when I got my N900 (I call her Betsy and introduce her to everyone as my internet bride).

I'm not a heavy data user and my occasional browsing on the bus was OK on 2.5g so I didn't change carriers.

(Ovi maps is a pain but I haven't used map loader yet.)

i changed from telstra to vodafone for the n96!!!!!!!!!!!

i'd been with orange for 10 years here in the uk. they don't seem to realise that the way people use their phones has changed..
anyway i didn't want to sign up for 2 years with vodaphone. especially since i'd need a femtocell at home.. so i bought the handset and got an o2 simplicity rolling 30 day contract.
Don't like to be tied down!

well not by a network

I changed because of simple calculation. For the same money I got double amount of data transfer. One had 1GB of data transfer the other 2GB for around 20$, that can be used in 60 days.
The other rates are around the same.
I use prepaid card. I could got more data transfer, 5GB, on postpaid, but then that amount is valid only that month.

Just switched carrier to have the n900 at a nice price

No need to change carrier, have had the best deal for my needs for two years. All carriers have good, working 2G & 3G here in Finland.

Yes. Boost to AT&T. As much as I hate AT&T, they have a far better PAYG data plan than T-Mobile USA, and where I live, EDGE is the best I'll find regardless.

I thought about it, thought about it hard when I got the N900 to review. But after walking my voice plan down a notch, and I'm technically off contract, I'm coming out a lil higher than would with T-Mobile.

Some of you considering unlimited data plans might want to take a look at this piece; the person is using Symbian, but tends to get around the unlimited data plan by smartly using WiFi. Such a case could easily apply with the N900 regardless of carrier. And it keeps things quite cheap.

I did.

I was going to swap anyway, because I wanted cheaper megabytes. But I ended up with a carrier I would not elseways have considered, because the N900 was in stock and on a good downpayment schedule. Half price up front, the rest paid over a year.

I didn't had the choice to change. I was with virgin mobile which doesn't support sim cards at all. And there is none carrier that supports the n900 for 3G for now here in Montréal. So I'm with fido. Just waiting for vidéotron to gives us 3G at an enormous price I guess!