It's considered "cheese"--in other words, it takes advantange of a hole in the game mechanics. Not saying you *shouldn't* do it; after all, you purchased the game, and you're welcome to do whatever you want with it. Just don't expect to earn a helluva lot of respect for announcing that fact.

It's been a regular item for discussion, up here.
I seem to recall that somebody did a bugfix for this--Baldurdash, perhaps?--but don't recall who.
Personally, I get the greatest thrill out of beating something fairly, not because I can plant traps in plain sight that the AI can't deal with.

But each to their own.
[ 12-20-2001: Message edited by: fable ]