T-mobile worked fantastic for me all times (except for inside of Soarin') - I am also Canadian, and what we do is, make sure our GSM cell phones (with sim card) are 'unlocked'... we then purchase on ebay a Tmobile SIM card WITH activation kit, OR one that is already activated that you can change the area code to an Anaheim one. We swap out our Canadian SIM cards for the USA ones once we land in the USA and sign up beforehand for the $2 or $3 a day T-mobile plan (MOUSEWAIT android, etc. app for use in the parks!) Facebook, email, web browser, and more.
It is far cheaper than any other method, when working with a cell phone that you already have, and hopefully I will be able to add a google voice number to that phone when I am there the next time. (Could be making free calls to Canada from what I hear, using the 3G connection. This will be new to me, if it works o.k.)
We use the Optimus One phone (Fairly cheap, $130 phone at Bestbuy, Futureshop, etc.) You can 'unlock it' (you are well within your rights to do so) from the carrier it is locked to, by purchasing a code on ebay, etc. Usually it is simple (enter key patterns) to unlock a phone, and then your phone can work with any sim card just by swapping out sim cards. The only exception is that lately, I see only 'HSPA phones' will work with certain SIM cards, etc., which means higher technology, but also means you can get some decent data speeds with the phone with T-mobile.
Just ask if you have any questions. I hated being without my phone in the years prior that we have done this. Roaming fees for Canadians to USA using a Canadian plan are ridiculously expensive! This way, if DH and I needed to split up with the kids to do something, he had a phone, I had a phone, and it was only around $1.50 a day back then ($2 - $3 each phone now) to call or text back and forth. Texting back and forth to Canada still costs money, I believe, on that plan, (perhaps 10 cents a text to and from) but using the 3G app 'whatsapp' on a droid phone, etc. could help with that... I haven't tried that yet, either.
Another thing you can do is sign up for the monthly BOINGO plan for your laptop, etc. at LAX and the Calgary airport. It is around $18 a month for 2 or 3 devices I think, and once you pay that one time monthly fee, you can cancel, so it won't reoccur. This would only apply to wifi devices such as ipod touch and laptop, etc.
Last time we went, I found the data plan with T-mobile to be more than we needed (didn't work on netbook, but on our phones it was fine) so the next time around I will not sign up with BOINGO but it WAS decent, and very reliable. Easy to cancel, too. BOINGO used to have a great connection at McD's on Harbor Blvd and likely still do, but I believe McD's now offers free wifi anyway.
Good luck with it all!
