Only Using Wifi Internationally - Sprint HTC TP2

[bleh345]

I will be traveling to the UK & Spain and I have the HTC TP2 on Sprint with MightyROM. So my question is if I just wanted to use free wifi over there exclusively whether on the train/hotel etc for free and didn't want to incur any sort of random roaming charges or whatever - is there a way to actually do that? Can I just activate the Wifi setting but will it randomly try to roam over there by itself still? Is there any way to shut off any type of roaming/voice features? How would I go about doing this? I called Sprint but they don't seem to know what they're talking about.

Thanks