Are there SEO implications to using drop down menus

I'm considering moving a lengthy list of category and date-based archives into a drop down list in order to clean up the sidebar on a site. Are there any SEO implications to doing this?

The items are currently in an unordered list.

Thanks!

 

im pretty certain there arn't. the content inside the drop down will be indexed

 

Most SE cannot read Flash or Javascript Menus.
In case you use those, you should have two versions and detect if the surfer has flash (or js) enabled. otherwise show a plain text menu.
DHTML should be fine, but I am not really sure.

 

Thanks - this drop down will just be a regular old form - no js or flash, just plain html.

 

Um. I am not really sure about Forms. It most likely depends on the implementation.

 

Forms are one of those things that you can't guarantee with search engines. Wht don't you use forms and also have text links at the bottom for your main pages. This will mean search engines definately won't have any problems crawling your site.
Have a look at my site http://www.BuildYourOwnBusiness.biz to see what I mean.