a ha-blast or HA-blast (if accented) is a quick flurry of H's and A's to express laughter via netmeeting. Occurs mostly while at work to limit the time the chat window is open and limiting the chance of getting busted by the boss.
Based on the concept of a single stroke blast-beat.
anon: oh man, that hurt!
me: HAHAHAHA
also can be used in place of HA's
e.g.
anon: I just got busted by the boss
me: <HA-blast>
RARFL
for use when you're too damn cool to use ROFL in type or phonetics.
Samuel L Jackson would use RARFL, though most likely while perfoming an internal monologue.
man, I RARFL'd so hard that my zipper broke and peas spewed out my nose