Hmm, del.icio.us comes with a pretty minimalistic design nowadays:

One problem with relying on (clever and smart as they might be) webapps (or building ones business on them – as recently promoted by Evan Williams and O’Reilly Radar) is: they do fail.

[Note to self: make an exhaustive list of current dependencies, evaluate the impact for worst and observed cases, come up with some sort of backup, interims, and exit strategies]