I would like to pre-present you portable bookmark manager called "Bookmark Base". It's already pretty stable so don't be afraid to work with it. I hope that less than in one week it will get a public release.
Here we have two download links:
[LINKS REMOVED BY MODERATOR]
It's simple and straight: import&export bookmarks between different browsers and stay portable. The most interesting features are bookmark checker and powerful category&bookmarks editor.
I would like to get a feedback from professional portable software users: is it comfortable to use, is it fast, do you like GUI and so on. The most valuable feedback providers will be rewarded with free registration!