If you get a list of domains which are soon to expire using XENU, pay for a service which will check the list 24h a day, so you can be sure to get all the gems.
There are many of these services, like expirefish, namewinner and so on... You should try all of them for domains which are soon to expire. This way you can be sure to get the name you want.
Have fun and make a shitload of money
