Portable Search Engine

I found a portable search engine - Gaviri PocketSearch.
It is not free, but does have a good free trial.
The limitation is 2000 documents, but I don't think most people will have that many documents on their drive.
The site does not mention any time limits.
It is also avalible as U3.

Site: http://www.gaviri.com/site/index.jsp
Download (Windows) (old version, see note below): http://www.gaviri.com/site/downloads/PocketSearch-1.1.1.exe
Download (U3) (old version, see note below): http://www.gaviri.com/site/downloads/PocketSearch-1.1.1.u3p

EDIT: They changed their site, new link. Also they released a new version, but the new limit is 30 days, and the old limit is forever and 2000 documents. So at the download page, look under old downloads. The drawback is that you don't get the new user interface, which looks much better.