May I add that when using outbound links, chose the link text carefully. Dont use the domain name or the Company name alone. Use a very short description, and see if you can use *your* keywords for it.
So if your site is about "beer" and you link to an overview of breweries in ... ummm ... let's say Hongkong (dumb example, I know):
Dont use
or even worse
but instead use
or maybe better
To cut it short: Use meaningful link text, preferably with your keywords in it (if it makes sense, of course).
And I would consider to abandon the dropdown boxes. Use normal lists, group them and write one ore two descriptive sentences for each group. Your site will gain in usability and have better content (at least for the spiders). What do you want more?
hth,
Alex