Which brings up the question -- most database tools I've used for ad-hoc queries have been mediocre at best. psql isn't bad, but a text based interface is suboptimal in many cases. On the other hand, SquirrelSQL, which I generally use, is adequate though not particularly friendly.
What I'd really love is a UI with some modern sensibilities, like saving all queries in history and providing Sublime Text like cmd-P commands to quickly recall and re-run queries. Auto-limiting, quick scrolling through query history with arrow keys, templated queries/ handling bind params, nice key mappings, SQL formatting, etc...
When I was using Oracle, Toad provided some of the above, but it was pretty bloated and provided way more than what I really needed. Tried navicat and it ate 100% of my CPU and crashed repeatedly. I'd be curious if there are any better (free or cheap) alternatives out there, but most of the offerings I've seen look pretty weak.