For example... keyword: "domain" shows 226,570 searches, keyword "domain.com" shows 3,225 last month (overture stat)
How many type-ins would domain.com get? 10% of the amount of searches made? Less? More?
Has anyone done any tests to see if there is a way to estimate type-in traffic based on overture stats for the keyword?
Another approach is to cross-match the stats from your 500+ parked domain portfolio with Overture results for the last 12 months.
Truthfully, the tools people employ to gain their competitive advantage - for example, projecting type-in traffic - are often generated at great expense, which usually means you either have to buy them or build them yourself.
The latest best trick for examining type-in traffic is to test register millions of domains for 4 days and then let them drop.
To answer your question directly the answer, for any one domain, is "no, I've not come across a tool that nails it for a 1 domain target" (though I'm certain the boys/girls with the 100,000+ domain portfolios have much better tools. :)
Here's a hopefully helpful tidbit: There's lots of domains that get more type-ins in a day than Overture reports for the same domain in a month.
Likewise, there are plenty of domains that get no reported type-ins in Overture that also get plenty of type-ins.
Finally, there are people selling domains that game the Overture results, so never buy an aftermarket domain based upon Overture stats alone. That should give you an idea of the importance of Overture domain+extension stats.
FWIW, Overture stats tend to be mentioned in combination of the reports of megadomain sales, but frankly the domain itself tends to tell you the story not the Ov stats. The big sale domains often have a long traffic history that isn't revealed at the time of the sale.