One Quickie
Processing every line in a string (NSString->NSArray)
Say you got a string that's composed of one interesting data item per line, like /usr/share/dict/words or from a script, and you want to process them. In this case turning a bunch of strings into floats:
NSMutableArray *altitudes = [NSMutableArray array];
NSString *altitudeString = [self altitudeStringFromGoogle: coords];
[altitudeString enumerateLinesUsingBlock: ^(NSString *line, BOOL *stop) {
float value = [line floatValue];
[altitudes addObject: [NSNumber numberWithFloat: value]];
}];