I was in Rome last week, and of course all the photos i took was to capture future Lego architectual details. My coworker got to hear: "This will be an awesome lego creation" a lot.
Anyway, after we saw Pantheon we walked by a little restaurant with an outdoor terrace where people could eat.
And there was a...
Moved the pic to flickr, Brickshelf kept loosing it.
It reminds me of your barrel a bit.
The tap is later added i can assume (doh!). But i think some barrels had the tap on the side. At least Tar barrels i think. (EDIT: if you images.google for tar barrels, all you will find is people carrying burning tar barrels on their shoulders...)
Anyway, since we need variation in tap location as well, this barrel could be created with your technique, but with one
along with the other 1x2 smooth plates and a tap attached to that. Or even with the tap left out, and let the stud on the one modified 1x2 plate be the hole where you "plug" the barrel.
(p.s. for future mocs, i think i will use my flickr account. the medium sized thumbnails are better to put in posts than really tiny ones)