eddit: Shop: iPhone UI Icon Set
http://www.eddit.com/shop/iphone_ui_icon_set/
The iPhone UI icon set gives app developers an extensive library of icons.
$70 worth of iphone toolbar icons. really nice set, but worth $70 for my budget app? ... hrm....A Favorite Data Structure « Rotten Cotton
Ullman Set: position[members[i]] = i
Ullman set, an excellent tutorial40 (NEW) & High Quality Icon Set For Elegant Designs | DevSnippets
High Quality Icon SetSet Operations in the Unix Shell Simplified - good coders code, great reuse
Very useful bash examples of operations with sets