likely lower weight (since they are potentially a somewhat hidden input) I have seen pages show up for words that were just in a dropdown form box though
I'm pretty sure that they're considered. I once came across to my name on a site written in a dropdownbox. And it's indexed by Google.
It's hard to tell the weight of dropdown keywords... But that site is listed even above the test exam results published in the official website of my university (.edu domain) in Google, for my name as the search term.
they are indexed, they are not given as much weighting though (at least it would not be logical to weight them as heavily). drop down menus are not always wrote in java.
I havent noticed any considerable differences... If you've got a drop down - use your keywords in it.... If you don't have a dropdown, I wouldn't bother adding one just to try and keyword fill your page, cause I really don't think it does much at all...
Not sure though, just haven't seen much help from it...