<human>: Can you give me the gist of the text in a nutshell?

I'm a Canadian traveling to the UK for 3 weeks in June, and I just realized that I haven't yet figured out a good way to be able to use my smartphone while I'm over there without incurring gigantic roaming charges.

I have a Nexus 4 smartphone with Koodo. Ideally, I would like to be able to use the phone over there as much as I do over here: as a navigational tool (GPS/maps), as a search engine on the fly, and perhaps for texting back home to Canada as well. At first I was thinking of just limiting myself to free WiFi only, but I realized this would severely limit what I'm wanting to use it the most for (navigation and Google while on the go).

Is there some way I can buy a prepaid card or something to plug into the phone so that I can use it over there on British networks for relatively cheap?

Any help would be AWESOME!
<bot>: traveling to UK, hoping there's a relatively cheap and easy way to get my Nexus 4 on UK networks so I can use it while I'm there