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!
also can be used in place of HA's
anon: I just got busted by the boss