Bibus has been suggested back in 2006 but the thread came to a halt. So here I go again. There has been some movement in the Bibus Forums to make it portable, see here:
Unfortunately I'm an end user, but if anyone had the time and the enthusiasm to give it a shot at pack Bibus portable (and posibly make it work with OOo portable) that would be great!
Since your posting I didn't know about bibus. I myself am using the Swiss reference manager Citavi since a few years and am very glad to have found it.
The current version is only in German, but later this year the version 3 is announced, which has a German/English user-interface. A preview of Citavi 3 is at the moment to be downloaded.
CitaviFree saves databases up to 100 data sets which is usually sufficient for work in schools or minor projects in university. Both Citavi 2 and Citavi 3 are portable (not PortableApps). If a user wants to have a special online catalogue to be integrated - apart from the ca. 4000 at present - the developpers will do that. There also exists a forum which is well-frequented (http://support.citavi.com/forum/index.php). Citavi uses .NET 2.0. And Citavi works with both MS Word and OpenOfficeWriter and OpenOfficeWriterPortable.
Perhaps this is an alternative for you.
I can use. From point of view the hardest part of a research paper is typing out the bibliography...
I'm tired of people living in their fantasy world when the clock is ticking away, and when they are unable to see reality for what it is.