My Domain Research

I have been literally domain researching for hours and hours. Here are some interesting 5 Letter domains up for grabs.
(I was looking for a domain to build authority site)

sipall.com
userall.com
nowive.com - I loled at this
eberb.com
ftcall.com

Some awesome domain research websites I stumbledupon
http://www.leandomainsearch.com/
http://www.domainhole.com/
http://domaingroovy.com/

More or less of a random thread.
Also If any of you have any suggestions regarding what I should name my review site pm me or post below.

Cheers!