Ran,
Thanks for your efforts in running the website and for soliciting opinions on improving it.
I have one minor suggestion.
Currently if I want to go "surf" the archives and see what threads were around at any given time, it's a little tricky because there are only links to page numbers that are close the one currently being viewed.
For example, if I am on page 1 of the DG, the following links appear at the top of the page:
Pages: [1] 2 3 ... 729 (so I can go to page 2, 3, or 729)
If I am on page 5 of the DG, the following links appear:
Pages: 1 ... 3 4 [5] 6 7 ... 729 (so I can go to page 1, 3, 4, 6, 7, or 729)
If I want to go to page 300, I really can't unless I manipulate the "start" variable correctly (which is a guessing game).
I would suggest that you replace those page links with a dropdown list of page numbers (1-729 or whatever the max # is), so that upon selecting a page number, the user is taken straight to that page.
(If you do split the DG into different categories, you could easily do this within each category.)