Google Wallet was introduced this week and it really wants to turn your phone into your wallet. Yes, we’ve heard that many, many times before but the partnerships with MasterCard, Sprint, Citi and some big-name retailers may make this a reality.

Google Wallet is an app that uses the NFC chip inside the Sprint Nexus S 4G to make secure transactions at retail establishments. Basically, anywhere that has the MasterCard PayPass system will be able to use this.

The Google Wallet will let you use a Citi MasterCard or a prepaid Google credit card to pay for things. It will also include things like your rewards card and even the Groupon-like Google Offers. The

The Google Wallet service is going to face multiple challenges from other competitors and even in the court, as PayPal is suing it for misappropriation of trade secrets.