Here are the main details on cashing cheques/checks from the US in American Dollars.

Yes, you can do it. Usually you won't be charged any extra fees. Sometimes, banks will put on a hold (if it is a personal cheque) of as much as 30 days. TD did that. 

Be sure to ask if there are any extra fees before you do the transaction! Though there usually shouldn't be any.

Compilation of US$ Bank Accounts Available for Canadians at Canadian Banks.

I've already written a guide here on getting a US-based US Bank Account as a Canadian. These have to be opened in-branch at a US Bank Branch. RBC, through its Centura operations can do it through a Canadian Branch (I think), but they're kind of expensive.

2012 FYI: I did end up getting charged the $25 annual fee, it just worked out that I got charged it as late as possible as it was charged on your anniversary date. The fee is rebated in future years as long as you do $1000/year, but you can't avoid getting dinged for it at least once.