You can now go CharlieCard-free on the MBTA. The new “Tap to Ride” system lets riders use credit cards, phones and even smartwatches to directly pay fares on buses and subways. Here are some tips to ensure your first ride goes smoothly.
For myself, I use the commuter rail and a monthly bus/subway pass, so this isn't terribly helpful. I haven't really kept up with this plan though, are they planning on including monthly passes in this in the future? Some transit systems let you put a pass into a mobile wallet and scan from that, so the tech is there.