Once you have adjusted the levels/curves of your photo as you would normally do, make sure the background layer is your active layer and then follow these steps:

1. Go to Layer > New Adjustment Layer > Levels
2. In the New Layer dialogue box that pops up, select "Soft Light" from the Mode drop-down menu
3. Click OK and another dialogue box will appear but behind that you should see your image is now a bit more "poppy"
4. In the dialogue box that just appeared, you can adjust the output levels bar to adjust the amount of pop by moving the light and dark sliders until you're happy with the look.

When you're happy with the results, why not show them off in the RebelEOS Flickr group photo pool.