So I know you can get Vim autocompletion with Ctrl-X, Ctrl-O but I'm wondering if you could rework it so it works with just pressing Tab (more like Textmate's snippets), or even just how I could remap it to something a bit shorter (even if I can't get fancy tab completion), as I find Ctrl-X, Ctrl-O a bit awkward.
Answer
I realize this question has been already answered, but you might be interested in a plugin such as SuperTab, which provides auto-completion and uses more than one type of auto-completion depending on the context and what type of completion you have been using.