to many links in the left (i'll make a dropdown menu for them) and to many products for the first page (first impression is that you have many different products, but you deal only with mailboxes, this could be good or bad ).
hm, personally i hate quicktime and flv ...
For designers i think uncompressed avi will be the best, but the size of the file is very big, i think you should put an option for divx, mpeg4 compression.