It's easy to string two or three porn words together to make a hot looking domain name, but is the result really useful. It may be good for flipping on Ebay, but if you want to sell to the knowledgeable guys who read the Netpond domain forum threads, you need something a bit better. You should discover your own quick test for evaluating potential buys, but here are three for a start.
Enter the phrase in quotes into Google, and see how many paid advertising spots Google gives you. If you don't get any, then it means that the traffic buyers don't think much of the name.
Type the phrase into Digital Point's keyword checker -
http://www.digitalpoint.com/tools/suggestion/ that will give you the wordtracker and overture counts for the phrase. Whilst I don't believe that domains help a great deal in SERP placement, they do help a lot in getting surfers to click on your entries, and they can get you some type-ins.
Enter the domain name with the .com, but without the www. into Google and Yahoo. That should show you some of the old links that are floating around on the net, and it can also give you some iteresting info about the name. For example, if it turns up in a list of refunded names, then it means a taster picked it up and dropped it because it didn't have enough traffic.