Depending on which version of Mac OS you're running (need 10.x for rBrowser), BBEdit works great with a program called rBrowser (more than just ftp).
By double clicking on a file in rBrowser, it automatically opens in the program I've predefined (BBEdit). Doing a regular save in BBEdit automatically saves it back to the server.
My suggestion, if you do a lot of code, the 2 are a must - hand in glove answer.
For BBEdit:
http://bbedit.com/products/bbedit.html
For rBrowser:
http://www.rbrowser.com