While English allows you to naturally create whole sentences using one-syllable words, it's horribly hard to even put two one-syllable words side-by-side in Portuguese.
That, and "W" takes only two syllables to pronounce, making the grand total six in an URL, the same number required to spell the dots (our domains end with ".com.br", making it three times the two-syllable word "ponto"). And now I remember "W" was not even officially considered a letter until recently, so abbreviations with it are rare.
Before considering a letter harmful, please mind the rest of the world that is also using it.
Just kidding... I usually say 'dub dub dub', except to very novice audiences.
What about H?
However it appears infrequently in written French -- the "w" sound, as it would be spoken in English, is written "ou" (eg "oui"). But in French, the letter w is only really seen in loanwords.
As a pun hack, run together Us. I refer to my university as Triple-U A.
