PNG ICO ICNS MORE
UI
Pixel
Fugue Icons
question
RoyalBlue
32x32
Desktop apps
Splashyfish
Information, Comment, question
DarkGray
16x16
Mixed
3D
Flavour Extended
?, Key, question
WhiteSmoke
48x48
Shopping & e-commerce
Smooth
Woothemes Ultimate Icon Set
exclamation, stop, Hand
Black
128x128
Tango
infomation, worning, Dialog
Tomato
PNG MORE
Twotiny
DarkGreen
10x16
Computer & hardware
ASP.NET icons
question, help
DodgerBlue
KDE Crystal Diamond
question, messagebox
22x22
Crystal Clear
question, glass, Box
Gainsboro
Mini
question, Info, help
CornflowerBlue