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 Some tips
The cell market is quite different in Canada than in other countries. You can get a pay-as-you-go SIM card from provider's stores, either at the airport or near the venue for about 10 CAD$. Data plans are quite expensive, so it may be advantageous to purchase an international roaming package from your regular provider. Note that WiFi is available here and there across the city, so you may be able to get by quite easily without a data plan.
 Table of providers and costs
This is provided purely as a demonstration of the above: this is probably too expensive if you come from the US or Europe, or, in fact, most parts of the world, where you're better off taking a special roaming service with your provider. Bottomline is that you are unlikely to find any plan with data under 60$ per month. The planhub.ca site has a good comparison of the cheapest options and best dataplans in Canada. Be aware that a lot of the packages described here and there cover monthly contracts, but a recent CRTC decision establishes clear rules that limit cancellation fees. In particular, for indeterminate contracts, cancellation fees are forbidden.
 Bell Mobility
- $15.75/mo: $0.20 /min. local minutes, unlimited SMS (canada), $0.40 /international SMS (sent)
- $20.75/mo.: 50 anytime local minutes, unlimited SMS (incl. international)
- $55.75/mo.: unlimited local, unlimited SMS (incl. int.)
No data included. add 30$/mo for 1GB data. At least 10$ activation fee.
 Rogers Wireless
"Smartphone plans": 70-100$/mo for 6-14GB/mo (includes -20$ rebate if you "bring your own device").
Owned by Rogers.
Plans: 65-115$ for 3-9GB, includes network neutrality destroying "spotify bypass", whoohoo!, 45-55$ for 1-2GB
 Telus Mobility
"Bring Your Own Device" plans: $70/mo, 2GB data 300 Local SMS unlimited Canada.
 Vidéotron Mobile
mobile plans: 30-70$/mo for 500MB-6GB
 Public Mobile
Buy a SIM card in Wal-Mart for 10$ then activate it and choose a plan online or by calling "*611" starting with 40$ per 1Gb at 3G speeds over 30 days (45$ for 2Gb, 50$ for 3Gb, LTE is 48$, 58$ and 73$). You can add province-wide talk and global SMS for 7$ (after discount). All values are without tax.
 Roaming from Other Countries
 Roaming from UK mobile networks
This is generally very expensive!
Data £6 per MB(!). (Canada is not a "feel at home" country so this is charged outside of inclusive allowance.) Calls £1.40/min, texts 35p.
Data requires a Travel Data Pass, £4/day (for 500MB/day) or Zone A roaming data add-on, £20/week (for 250MB/week), £40/week (for 750MB/week), or other options. Calls £1.00/min, texts 40p.
Data £6 per MB(!). Or purchase Data Abroad Bolt On, £120 (for 200MB/month) Calls 80p/min, texts 40p
World-traveller plan is £5/day flat rate.
 Roaming from German mobile networks
Prepaid: Data requires Travel & Surf DayPass M, 6,95€/day (50MB/day)
With contract: 0,49€/50KB(!!!). Or purchase Day Pass M, 2,95€/day (for 50MB/day) or WeekPass, 14,95€/week (for 150MB/week)
Data is all-inclusive if you have the MagentaEINS contract with the MagentaEINS EU-Flat Plus add-on
Calls 1,49€/min, texts 0,49€
For users of Red, Smart L and Smart XL contracts the EasyTravel options are available. These allow up to 500 minutes of voice and 500 SMS per day for free to Germany or Canada, data is available on the same terms as in Germany per your contract.
If you have the EasyTravel Tag option active on your contract (verify!), any use of the phone (voice or data) will automatically activate EasyTravel Tag for one day (midnight to midnight German local time) at a cost of €5.99. Alternatively you can activate EasyTravel Woche for €19.99 which offers the same terms for a continuous 7 days.
 Roaming from US mobile networks
It *might* be possible to roam on the Videotron network with a prepaid SIM from Eastlink Wireless:
http://www.eastlink.ca/wireless/prepaid/plans.aspx $10 for 0,25c/MB => 40MB or $35/30 days (for 250MB/30 days)
 Roaming from Hungarian mobile networks
Data 236.93 HUF (~ 1.13 CAD) per 100KB(!).
Calls 325 HUF (~ 1.56 CAD)/min, texts 122 HUF (~ 0.58 CAD).
 Roaming from Mexico
Telcel offers free or very cheap voice and data roaming in US and Canada.