Serbinski Accounting Firms

I expected to file US taxes - just wanted to make sure this didn't result in getting double taxed on my Canadian income. I really just want these US accounts open to pay for my XM radio, paypal purchases, finish paying student loan, football tickets, etc... So with no downside I think I'll keep that...

I'm a dual US/Canadian citizen - moving back to Canada end of September. Can I keep a US checking account open (used to payoff my student loan) and keep a US credit card - or would this give the IRS reason to believe I'm still a resident..and tax me accordingly?