From one of the founders of modern software (Mitch Kapor) comes:
Foxmarks Bookmark Synchronizer automatically synchronizes your bookmarks between two or more computers running Firefox. It also lets you access your bookmarks from any computer anytime via my.foxmarks.com. An easy-to-use wizard guides you through the quick startup process. Then Foxmarks works silently in the background to [...]

A nice recommendation from LifeHacker comes in the form of Net Profiles:
Freeware application Net Profiles lets you automate tasks—like mapping network drives or switching the default printer—based on the network your computer is currently connected to.

Netzgesta makes making frames easy (through JavaScript):
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