Being a true LOST fan (completely devoted each and every week), I have to say that last night's episode blew my mind. I'll be watching it again tonight on abc.com digital re-runs.
It was awesome, and to check your own LOST knowledge, visit EW.com's Totally Lost recaps, videos, etc.
"Watch with Kristen" from E!Online has great coverage too!
There's some awesome theories happening on Huffington Post as well.