If you look at the Add Issue form on the Demo issue tracker you should see the three select boxes (aka. drop downs) and if these become too long they tend to be difficult to use. Here's a potential solution that; I just need to know what you people thing about it's usability.
onblur() to change the
size attribute of the select input element thus temporarily giving the user a bigger workspace. Please have a play on this demo page and return here after for feedback.
The disadvantage with this, in terms of usability, is that it's unexpected and might not work exactly the same in all browsers. When the drop down expands it also shifts all surrounding content downwards which might make the user feel dizzy when the page "flickers".