I presume that you want to move up to one of the higher grade lens or maybe the ED 18-180mm. It is hard to recommend a lens not knowing your shooting habits.
The 50mm is a nice lens for portrait and macro (not really true macro though unless you add the extention tube). It is light and sharp and easy to get along with but the 100mm focal length (in 35mm terms) is not the focal length I want to shoot in all the time. The 14-54mm is a very nice walk-about general purpose lens and also a joy to use and I've gotten some very nice results with it and it is a very close focusing lens, even closer than the 50mm.
Like I said earlier, I love all of my Oly lens' but as far as sheer performance goes, I don't think the 50-200mm and the 11-22mm can be beat -period (unless perhaps it's by one of Oly's $$$ "super high grade" (their terms) lens' (at which point one begins to wonder when the point of diminishing returns starts to kick in :O).
Of course, these are more of a specialized lens and you certianly wouldn't want to carry around the 50-200 all the time but the 11-22 at the long end (22mm) does come close to being a "normal" lens (in 35mm terms). One of my cameras (usually the E-1) always has the 11-22 and the other camera (E-500) usually has the 14-54mm on them. But I love it when ever I need to whip out the 50-200
BTW, what are your shooting habits besides flamingos?
P.S- What ISO did you shoot the flamingo at?