Is it possible to use Tokyo Cabinet with any of the .Net Languages, preferably VB10? How about Tokyo Tyrant? Preferably without going through LUA/Ruby or other wrappers..
If there's no easy way in doing so, can you recommend other fast Key-Value Database which can be used?
Check out CouchDB. The only .NET wrapper I know of is SharpCouch, but you could also access it using the database's native RESTful HTTP API. I imagine there are a few other wrappers out there by now, but I don't know of any others off hand.
I've just published a .NET wrapper for Tokyo Tyrant on CodePlex. It supports the key/value interface as well as the table database mode. It also has a comprehensive example app that should get you started quickly.