Other favourites:
- dub-dub-dub
- wah-wah-wah
- web-web-web
- double-yous
The key is, more-or-less: one character, one syllable (at most -- anything pronouncable such as "org" should go monosyllabic too). Hence also "dot" (or "stop" if you must), and "slash". What about "colon" though? Guess that has to stay.