MasterCard demonstrated the Google Wallet application, which is scheduled to launch soon.  Running on Sprint’s Nexus S 4G — with a planned expansion to multiple devices — users can connect a Citi MasterCard account to the service, and tap-to-pay at any retail location outfitted with a PayPass station.

The transactions take place as instantaneously as you’d expect, with spending alerts notated automatically in-app, as well as via text message.  Currently, the Google Wallet service is Android-only, and that’s probably a direct result of the AT&T, Verizon and T-Mobile backed mobile payment rival, ISIS.

Read more, via Engadget.