I've done a lot of green-screen work in my career. At my last post, I did several videos that were almost all shot on green screen. For one client, we shot 20+ interviews, all on green, then composited them over the graphic background in post using Serious Magic's (now Adobe's) Ultra 2. It looked really cool, but took forever!
The other day, I was poking around Joe Wiggleston's site and noticed some new clips he put up. One was a 10B4 that NorthPoint uses each week. The host was keyed over the background, and it looked pretty good. So I asked Joe what they were using for the key. He told me that NP uses Keylight from The Foundry. I've played with this software, and it's good (and it comes included with After Effects CS3 Pro). It is RAM and processor intensive, though.
Then he told me he personally likes dvGarage's dv Matte 3 Pro Studio for keying right inside of FinalCut Pro. Being the curious sort, I checked it out. I didn't plan on spending 2 hours at their site, but I did. Let me tell you, the software looks amazing. The green screen removal it does is so clean, so fast and so easy, I was stunned.
DV footage is notoriously hard to key because of the 4:1:1 color space. That means that the color information is only 1/4 of the resolution of the luminance information. Because keying traditionally relies on color info, when you key DV footage, you end up with a rough and jagged key. Their software uses information from the luminance channel to help clean up the key, and it makes a huge difference, even with HDV footage (which is 4:2:0, but compressed with MPEG2, not a keying-friendly format).
They have another product called dv Matte Blast that does green screen removal in real time! Another product, Conduit Live, will take any video input you have, and remove the green screen live (!), and allow you to test it out over a background. They even keyed water, live, over a background! Very cool.
While I've not had much occasion to do a lot of keying here at Upper Room, I'd really like to. Once we roll over to the next budget year and I have money again, I would like to get a flexible green screen and start shooting interviews over that. Then, if we want to put people on black, white or a background, we can. I will definitely be looking to pick up dv Matte 3. Once I do, look for a full review. They also have full trial versions available on the website, so check them out.