"Your long-winded post/response left me tongue-tied - other than to say: "hm"
"I didn't grasp your confusing (or too technical) posting"
"I'm too dumb or dizzy to word a response"
OR: "I see... sorta..."
(yet another e.z. way to post a think-free acknowledgement)
Quick way to post expressions of sympathy (or self-pity) i.e. "aw, too bad..." "sigh, sorry 'bout that"
"Oh, I see now..."
"Aha, I see what you mean..."
The remaining smilies are self-evident (or alternate versions)