Cheapest way to use my phone in US/Aus/NZ

Hello,

I live in the UK, and currently have a Samsung S2 on Tesco's (which I think is O2). It's an initial 12-month contract which is due to expire in August 2012.

In July 2012, I am going travelling for 6 months, to the US, Australia and New Zealand with one friend (2 months in each place).

I was going to cancel my Tesco contract, as it's only 1 month of paying without using it, which I can live with as it's £10 a month. The current contract is unlimited texts, 500 minutes, 500Mb data.

I use WhatsApp on it to text my friends in Australia for free, and it works really well.

When I'm in the US/Aus/NZ, I won't be using a mobile to phone anyone or text anyone, but I would really like internet access, so I could use WhatsApp to text home, and to keep a running travel blog (using Wordpress) which I can update through my phone.

Is it possible to just plug in an American SIM card into my existing phone, and somehow, get a 2-month contract that gives me no texts, no calls, but free (or very cheap) internet? Likewise for Aus/NZ? Or a PAYG SIM that offers cheap internet access? Here in the UK, I can leave the internet (WhatsApp) constantly "on" waiting for messages, so I can respond to people pretty much instantly, but I'm assuming I won't be able to do that abroad?

I did also like the thought of getting two SIMS and giving one to my travelling companion so if we get separated etc, I can phone her, so perhaps I do need a few calls. I don't know the best solution for me.

I'd ideally love to keep my S2 because it's a large screen, with a great camera, easy to type lots to update a blog and I can watch videos etc while I'm bored, but perhaps a solution is to buy a cheap throwaway US/Aus/NZ phone+SIM combo? Again, I'm a bit confused with my options and the best solution?

Also, to throw into the mix, I'm not sure if my S2 is tri-band? How do I find out?

The overwhelming important thing is to keep costs down, and balance that between staying in touch with home, and perhaps being able to stay in touch with my travel companion.

Can people give me a bit more information, and their recommendations?

I'd really appreciate it.

Thank you.

The Samsung Galaxy S2 supports these freqs:

Voice3G Band 850MHz, 900MHz, 1900MHz, 2100MHz
Network&Data EDGE on 850MHz, 900MHz, 1800MHz, 1900MHz; 3G on HSPA+ 21 (UP) / 5.76 (DL)

And you can check which countries use what freqs here. I think you will be fine.

Best thing to do is ensure your phone is unlocked from your current provider, buy a SIM (voice + data) PAYG in each country you go to. This is the cheapest option but of course it means a different number for each country you visit.

good luck!

OK great.

So, if I get it unlocked, buy a SIM in America, plug it in, and then turn everything off (data roaming, internet etc) and then only use it for very infrequent texts/calls/WhatsApp/blog updating (I can write the blog offline on my phone and then turn internet on to upload it), then it should be pretty cheap?

If I leave the internet on all the time, like I do at the moment, but disable some apps, so the only things using the net would be the email sync, Whatsapp messages, and the browser when I'm using it.....does anyone know the likely cost of that?

OP it depends on the plan you get for the SIM (voice + data PAYG plan).
Some plans are for ppl who like to SMS/text and a bit of data while others cater for lots of data but few SMS and phone calls. So check out the details of the plans carefully.

I just checked Verizon (as an example) - there is a USD$50 / month plan for unlimited voice and data here
You can check Sprint and others and see what they have.

Good luck.

Careful! Verizon and Sprint are not GSM operators.