NSError* error = nil;

    NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern:@"(?:\\s|\\A)[##]+([A-Za-z0-9-_]+)" options:0 error:&error];
    NSArray* matches = [regex matchesInString:tweetText options:0 range:NSMakeRange(0, [tweetText length])];
    NSString* processedString = [[tweetText copy] autorelease];
    for ( NSTextCheckingResult* match in matches )
    {
        NSString* matchText = [tweetText substringWithRange:[match range]];
        NSString *matchText2 = [matchText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
        NSString *search = [matchText2 stringByReplacingOccurrencesOfString:@"#"
                                                                withString:@""];
        NSString *searchHTML= [NSString stringWithFormat:@"<a href='https://twitter.com/search?q=%%23%@'>%@</a>",search,matchText];
        processedString = [processedString stringByReplacingOccurrencesOfString:matchText
                                          		             withString:searchHTML];
        NSLog(@"match: %@", processedString);
    }