For those out there who want to figure out what Nagoyankee and I and duo797 are talking about, try this:
1. start saying "hee hee hee hee hee" with no gaps between the "hee"s
2. now try to abruptly stop a "hee" and have the "hee"s become separate sounds instead of flowing into each other
3. that pause is the same thing as a っ.
I attempted to explain in this video, but I wouldn't be surprised if my accent is heavily gaijin. I was more focused on explaining the っ. I know, academically, what it should sound like. I hope I pulled it off, but we'll find out if some native speaker wishes to pwn me to Andromeda.
YouTube - little tsu explanation