To get to beginning-of-line instead of top-of-document, I think you use control-Home or shift-Home in most OSX Apps .. it's cmd–← (command plus left arrow) — i forgot to include that information in my previous mail and didn't want to spam the list, so i sent the follow-up to sergey only ... but now i can't resist letting everyone know ;)
i'd try out what ctrl-home and shift-home do on my mac, but i don't have a keyboard with a home key here at the moment ... not that i'd want one; those overly wide keyboards are stupid, awkward, unergonomic, pointless abominations ... but that rant would be off topic here so i'm leaving it out ;) anyway, i don't think any meta key would usually modify the behaviour of 'home' on the mac, outside of weird apps. oh, btw., ctrl-home is top-of-document under windows; on the mac that's cmd–↑.