NSOpenPanel *panel = [NSOpenPanel openPanel]; [panel setPrompt: @"Stuff for the Choose Button"]; [panel beginSheetForDirectory: nil file: nil types: [NSArray arrayWithObject: @"buf"] // or other file types modalForWindow: window modalDelegate: self didEndSelector: @selector(openPanelDidEnd:returnCode:contextInfo:) contextInfo: nil];and the didEndSelector implementation looks kinda like this:- (void) openPanelDidEnd: (NSOpenPanel *) sheet returnCode: (int) returnCode contextInfo: (void *) context { if (returnCode == NSOKButton) { NSArray *fileNames = [sheet filenames]; NSLog (@"wooOOooot! %@", [fileNames objectAtIndex: 0]); } } // openPanelDidEnd