[puns]

While less is more in online forms is good advice, the thing about 7 items is wrong in this context. This is because while you may only keep 7 items in your head at any time you're not actually using this skill when filling out your form -- you're just scanning down the list for a particular item you need, not trying to memorize the whole list. Even if you're trying to choose between comparable items, you're still memorizing those few items, not the whole list.

[ams6110]

Agree, seven is a pretty small and arbitrary limit for a drop-down. I think maybe 20 or 25 is a better limit, and certainly not so many that they won't fit on a typical 1024x768 display (less if you're supporting small/mobile device displays explicitly).