Check with your university or hospital library. Many have subscriptions to MD Consult and many have remote access so you can access from home. I have access to MD consult thru 3 different associations!!!
As for other sources - I don't know of any. Some textbooks give you a CD with the book on it and I know in my program these CD got loaned around so everyone could "borrow" the information.
I think if you join ACS you get access to on-line stuff, including their textbook. I don't know of too many surgical texts which are on-line and have been purchased, but as tussy notes, check with your med school library.