I can attest to the fact that both sellers and buyers love photo CDs with a slide-show or virtual tour on it. I've been doing this for years for all our sellers and many times buyers actually ask for them too. Being a Realtor I give them away to get referral business in the future and because I like doing it. Real estate photographers be aware that Realtors are always looking for a nice little gift to give their sellers at closing so if you can offer Realtors a snazzy little CD with all the photos you took of the home and have it packaged nicely like Cherie describes you can sell your photos again on a different medium.
I think packaging for kind of product is important. Cherie's comment describes how she prints on the CD. This is a nice touch but if you don't have the right kind of printer to do this you can also print CD labels and/or CD cover labels. What I do is use mini-CDs (3.5" in diameter) that come in little plastic CD covers. I print an insert for the the CD cover that has a front shot of the home, it's address and our phone number and logo on it. One seller liked the CD I gave him so much he ask for one for each of his 5 kids.
Cherie creates her CDs with Photoshop Elements 5 but don't forget, you can also burn a cd like this for free with Picasa 2.