Yep a quick search of google for Yahoo keyword tool found http://inventory.overture.com/d/searchinventory/suggestion/
Don't count on inventory/overture to be 100% accurate. It is a great tool but don't rely on it totally.
This php scripts (tools) might help you. BackLink Research Tool Bulk Alexa Ranking Checker Bulk DMOZ Listing Checker Bulk Keword Research Tool Bulk Link Popularity Checker Bulk PageRank Checker Bulk SE Saturation Checker Content Size Ratio Calculator Deep Link Ratio Calculator Indexed Pages PR Checker Keyword Competition Survey Keyword Density Analyzer Keyword Suggest Extractor Keyword Typo Generator Meta Data Extractor Multi DC Link Popularity Checker Multi DC Page Rank Checker Multi DC SE Saturation Check Online Link Popularity Survey Online Link Status Checker Online Page Survey Outbound Links Checker Overture Advertiser Search Search Engine Extractor Search Engine Rank Checker Search with PageRank Server Headers Checker Sitewide Cache Inspector Sitewide Page Rank Inspector Website Keyword Harverstor PM me if you need them.
Correct. You can also use the keywords tool in your AdWords account. It's not as narrow as Overture, but it's more current, at at times more helpful. Best used in conjunction.