do you want to stay "buddies" for the near future and keep her guessing?
then get something like a framed movie poster of the favorite movie you have seen together or her favorite movie:
http://www.nostalgia.com/
do you want to keep it even keel, status quo?
something classy from Red Envelope says I like you a lot:
http://www.redenvelope.com
if you think you may want more in the future?
get a more traditional romantic gift, but something smaller and low key: a nice piece of jewelry that complements something she wears often or looks great in --- will show you put a lot of thought in it. we love thoughtfullness even if you are not commiting
Don't want to order online, or you want to see it in person to check the quality? Do a simple google search for "gift shops in (your town here)"