I want to use n900&maemo as a portable library or more like an "in-your-pocket offline knowledge-base" solution with easy search capabilities. I have a few gigs (let's say under 15gigs...) of pdfs and html docs, with some powerpoint and msword file lost amongst them.

And I need something like beagle or tracker that can index everything and do full text searches blazing fast ("as you type" fast I mean). Can I run beagle or tracker on maemo or is there some better alternative?

I want to just select a folder to index all its content (recursively) and do the re-indexing manually. I want to be able to open, for example the pdf file where some text was found, directly at the page where it was found (or be presented with a list of "contexts" - like the paragraph where the word was found, if there were multiple matches - and click one of them to go directly to it).