I currently have a contract phone from the UK and pay-as-u-go thai sim that I use on my old handset (Thai GSM). As my contract has run out with Orange, I can either get a new phone for free by renewing my contract (M8800 or HTC Touch HD) or get a new phone with a different provider (I was thinking of t-mobile's G1).

I want to know what kind of connectivity I can get if I am spending my time between Bangkok, Bang Saen. Sri Racha and Pattaya. The phones hav HSDPA, but from what i read, thailand doesnt. Can the phone use Edge? Am I better to keep using it with my UK sim, or getting another thai sim (I currently just use a pay as you go 121 sim which flashes up annoying adverts every few mins and my UK sim in a different phone for when i am overseas). What is the best provider to use in thailand if I am better to swap over?

On a slightly differnet note, is it cheaper when overseas (non UK and non Thailand) to use a UK mobile or a thai one? I have just been using my Uk phone when overseas as it is on a monthly contract.

I hope my waffle and questions make some sort of sense, but if not, I am sure i will get flamed soon enough....

Too many questions in one post

The G1 will work fine as a phone here as long as you get it unlocked. Ask T-Mobile about being able to put in a Thai SIM card - there's usually a fee for this, but they usually do unlock the phone.

Use a Thai Sim, or pay ridiculous roaming charges - your choice!

The G1 has EDGE (class 10)

There is no HSDPA in Thailand

12call is just fine, DTAC is also fine

Don't know about overseas - but prepaid cards usually don't work outside Thailand, at least that was my experience with AIS. My post-paid DTAC also didn't work many places. I'd think T-Mobile has probably much better international coverage, ie it will work anywhere in the world (as long as you give them EUR 1,50/minute )

Pretty much everywhere you'll be traveling will have Edge reception, both on Dtac and AIS.

They both offer mobile internet on pre-paid simcards, call customer service to set you up with a cheap internet package (I have 50 hours/month for 267 Baht on AIS's One2Call sim), just make sure you have enough credit on the sim card. They don't have data limits here in Thailand.

Ais's One2Call works abroad on roaming, not sure for internet though.

Internet wise expect speeds of between 80 and 200 kbps (double to 5 times dial up speeds)

Splendid, thanks for the info guys.