Silly Japanese number joke/abbreviations:

[ishiyakazuo]

4649 = yoroshiku
881 = hayai
889 = hayaku
999 or 39 = san-kyuu (thank you)
53 = gomi
19-nichi = tookunichi (talk day - NTT's day for reduced rates)
su su su su (or just su4) = sushi
ba ba ba ba ba ba ba (ba7) = banana