1.) always do your domain searches on http://www.internic.net/whois.html so you can be sure that they're not being registered as you search for them.

2.) Read http://www.thenameinspector.com from beginning to end

3.) Come up with words that describe your ideas then use thesaurus.com

4.) Look to chop words down by syllables and then combine. ie. a personal bookmarking service or online profile service that was described as "my highlights" would become mylights.com.