I've been harvesting keywords and domain names for more than 3 years:
77,000,000 English Keywords new! The primary use of it is generating doorways; a bit less popular application is "White-Hat SEO." It's a really good product offered at a very good price. Similar databases cost from $8,000 at Keyword Discovery to $25,000 at WordTracker. This database contains all the information you need for picking good keywords and building massive keyword lists.
Database of English Similar Queries Per se "clouds" of target keywords. For instance, the inferences around the "web hosting" keyword will include "dedicated server", "unlimited bandwidth", etc.
30,000,000 Russian Keywords It's primarily used by Russian White-Hat SEOs. It's a good product; however, it has less data columns than does the English keyword database. Nevertheless, I haven't found a fair replacement for it yet.
Database of Russian Similar Queries (included in the Russian Keywords Database package)
Database of French Similar Queries (included in the French Keywords Database package)
16,824,843 .com .net .org domains The database contains 16,824,843 domain names, each one of which is in top 100 of Google search results for any of the 44,000,000 keywords from our keyword database. You can use this database to pick domain names that contain any given word or phrase.
Xedant Keyword Harvester One of the best freeware webmaster tools for harvesting ("grabbing") keywords from Meta Keyword Tags, HTML tags (e.g., the Title tag, H1 to H5 and Alt tags) and Website Content of Top 10 search results with Google. Spy on hundreds of your competitors in minutes.