Convert NSString to NSURL
NSURL *fileURL = [[NSURL alloc] initFileURLWithPath:filePath]; /* OR */ NSURL *fileURL = [NSURL fileURLWithPath:filePath];
Convert NSURL to NSString
// The output string will have the file:// prefix NSString *filePath= [fileURL absoluteString]; // The output string will have the file path only NSString *filePath= [fileURL path];
Updated @ 2011-01-10: Thanks for the comments of Brandon and Antal.