Flash for D5100
If you would like to have a TTL under 150 bucks, my vote goes to Yongnuo YN-565EX ETTL - http://www.amazon.com/Yongnuo-YN-565EX-Speedlite-Flash-Nikon/dp/B006R6TUJI/ref=sr_1_3?s=electronics&ie=UTF8&qid=1352357009&sr=1-3&keywords=yn+565
It is a powerhouse slightly weaker than SB900.
|Douaumont Ossuary by Eric 54-BNF|
from Armistice Day
|Silhouette at sunset by Jill Hancock|
from Portrait Lens (around 80mm or equivalent - please check the full rules)