Today is a good day for STM users. No longer do you have to deal with the panic of remembering that you need to fill your card, and then scrambling to make it to the closest station or pharmacy.
The STM has rolled out an all new system so that you can charge your card from home, which is great, but be warned that it is going to cost you $14.49. (But are we at risk? Montrealers are concerned that these cards may now be hacked) To reload your card you'll have to purchase a USB card reader, which you can find here. Seems a little excessive if you ask me, but if it means that I can reload my card without even having to get out of bed, I'm all for it.
Once you've got your card reader and connected it to your computer you'll be able to buy your tickets online and put them directly onto your card. As of right now only full fare and reduced fare weekly and monthly passes are available through the online service, but hopefully they'll expand it soon.