Long life mobile needed

i took a sagem my150x to thailand and hong kong - very cheap simple phone with a long battery life. rugged and great to sling in your pocket. dunno if thailand does them but hk had mega cheap sims (about a fiver) which effectively logged your call through a sort of skype set-up and made for extremely cheap, and i mean around a penny a minute, calls to uk.

my150x can be had for around a tenner here and there - you need to unlock it, i got mine dome via mobyrepairs on this forum for £7

Be aware that mobile connection in these countries are not so great,only biggest towns covered,and quality is poor,so you maybe considering not taking mobile at all Use walkie talkie to comunicate.

Why do you need a tri-band?
Why do you need a long battery life?

Just use your normal phone, but be sure to use a local sim as your UK sim will have expensive roaming charges over there, over a quid a minute using my Virgin sim in Asia.

If you are thinking of buying a phone, have a wander around the MBK shopping centre in Bangkok for decent deals. Should be easy to pick up a charger with a travel friendly plug as well. Loads of places to buy phones over there.

In Thailand the one2call pay-as-you-go sim cards are widely available, and extra "load" for them can be purchased at any corner shop, in values of 100, 300, and 500 baht, think there might be lower values as well. Just scratch the back of the card to reveal the code, and load your phone.

If you are making international calls from Thailand, there is a prefix (7 or 9, I forget which) which can be used for cheap international access, ask about it when you are over there. I think it just reroutes your call over a voip network.

Until recently it was difficult getting a sim In Cambodia, they are now available, but I have never used one myself, I always use Skype when I am in Phnom Penh.

Hope this is of help.
Dave..