We've identified a bug that may cause, under certain circumstances, periodic freezes of the Firefox UI, in terms of a short freeze every about 9 minutes. This only affects a small amount of users, so, if you don't notice this behavior, you can stop reading.
As part of the Memshrink effort, we reduced the SQLite page cache used by Places. This is not a leak, the page cache is actively used by SQLite to improve performances by reducing disk I/O. Originally Places was allowed to use a large cache (maximum 6% of physical memory, per connection), to ensure responsiveness of the awesome bar.
Based on the useful article from Ehsan Akhgari and the comments to that article (especially the nice suggestion from Daniel Holbert) and in the need for easier ways to backout stuff from mozilla-inbound, I've put together a couple scripts I use to easily (and more safely) backout, I'm going to share these with you, in the hope they may be useful and hopefully improved!
Listening to feedback I got from some user on my blog, I've put together a couple experimental restartless add-ons to solve some specific needs.