Can i bring my Verizon Iphone over to Tmobile?

I have an iphone 4 with Verizon and it is about $110 a month and i'm sick of it. The only problem is the Verizon iphones do not have a sim card slot, is that going to be a problem?

Yes, that will be a problem. T-Mobile only works with phones that have SIM card slots. Your iPhone 4 can only ever work on Verizon (and even if your iPhone 4 DID have a SIM card slot - for instance it was AT&T - you would still also have to unlock it first).