How about tickets to see her favorite show or performer? The tickets could be either for a show in your hometown, or incorporate it into a trip somewhere. (I love Tom Jones, and would be thrilled to get r/t tix to Las Vegas to see him at the MGM Grand, for example.)
Also, do you have a hobby that you could incorporate into a trip? Wine tasting in California (or Australia!) might be one idea if you like wines. If she has a favorite food, you could fly into a city that is renowned for that cuisine, or has a special restaurant.
Even if she loves to read and has a favorite author, you can check the web and see if that author is having a book signing somewhere, and then fly in and make a trip around that.
You can really make this into something that is as simple or elaborate as you want.
Hope that gives you a little start.