PlexDomain: Domain Analysis Tool.

It supports:
POWERFUL DOMAIN SEARCH
Deleted
On-Hold
Real-Time Newly-Deleted
Expiring Soon
Available for Registration
Registered Domains
REAL-TIME NEWLY DELETED LISTS
DIRECTORY CRAWLING
FILTERING DOMAINS

It supports filtering domains by searching number of links in:
AltaVista AllTheWeb Teoma Alexa AOL HotBot Lycos Google DMOZ
LookSmart MSN Yahoo
POWER SEARCH FOR AVAILABLE DOMAINS - It takes list of keywords from a file or user-input, creates a combination of domains and checks which one are available.
SUB-DOMAINS SEARCH
SIMILAR-SITES SEARCH to keep up with the competition
LINK-TO SEARCH to keep up with affiliates and partners
MULTI-THREADING
SCHEDULING BATCH JOBS
WHOIS RECORDS STATISTICS INDIVIDUAL LINK POPULARITY LINK RANKING
KEYWORD SUGGESTIONS REAL-TIME KEYWORD SEARCHES/TOP KEYWORDS
REGISTRATION, MONITORING AND BACK-TRACKING

PlexDomain: Domain-Name Search, Generation, Popularity and Analysis Toolkit keywords: domain, traffic, expired, deleted, popular, ranking, search, engine, directory, yahoo, dmoz, lycos, hotbot, msn, aol, alltheweb, looksmart, keyword, suggestion, hot