I know very few web frameworks which have Arc's style of implementing user actions, and for good reasons: either you've got a huge memory leak, or links have an expiry date. (I got a deadlink-error while clicking on reply...)
I have a hypothesis about bloating memory: it will stop mattering soon. Solid-state non-volatile storage at RAM speeds on a fast bus will allow for terabytes of memory -- and increase with the unimpeded Moore's Law of storage. I know of at least one company, FusionIO, offering this as a product already.
If you can store all but the largest databases in memory, why not use a web framework that doesn't bother with a "real" DB like MySQL? But clearly, I'm talking about memory hungry systems generally, and not memory leaks.
You can set an explicit expiration or have the links gced fifo. I used the latter in the example (and the reply form), but for something more critical (like YC funding applications) I'd add an explicit expiration. It's only one more token.
