You can dump your glass filters (well, some of them) and use Tiffen's virtual filter plug-in software after the fact.
What it does: Tiffen has spent many decades producing glass filters for photographers, but digital technology has rendered many of those filters unnecessary. In fact given their expertise in the real thing, it's no surprise that Tiffen's DFX Version 2 offers so many powerful virtual filters—and then goes farther. In addition to graduated filters, diffusion filters, starbursts and polarizer effects, Tiffen DFX also can emulate infrared, night vision, the lighting effects of silver and gold reflectors on faces (even when there originally was none), and more. The effect of each filter can be infinitely fine-tuned—something you couldn't do with the glass variety.
Who it's for: Hobbyists and professionals who don't want to schlep all that extra glass with them any more.
What else you need to use it: Windows XP Pro, XP Home or Vista, Mac OS X 10.4 and above. Can be used as a standalone program or as a plug-in for Photoshop and Elements, Apple Aperture, Adobe After Effects, Avid Editing Systems, and Apple Final Cut Pro.
Cost: $100-$300, depending on configuration
Before and after examples (photos courtesy Tiffen):
Before and after applying black-and-white infrared filter.
Neutral Density Graduated filters, a popular choice for landscape photographers, can be adjusted in post production.
SoftFX, a soft-focus filter, is similar to Tiffen's glass filter of the same name.