Google Adwords: Keyword Tool – Check popular keywords and get suggestions on alternative keywords.
SubmitterBot – Submit your website to huge bunch of web directories.
Google Insights for Search – Check keywords searches based on location and other variables.
ValueMyWeb – Get a rough idea on your websites value based on popularity.
KeywordSpy – Check your competitors PPC keywords.
Google Search Based Keyword Tool – Check keywords search volumes, based on real searches.
Google Trends – See what people are searching for, now and in the past.
WordTracker – A good alternative to googles keyword tool.
NicheBot – Another good keyword tool.
Alexa – Provides a good insight into a website traffic rank, but also has some other useful features.
