Oh dear. I like up to date SE databases. However, Altavista and Fast are starting to put a real strain on things. The number of requests they can make in a week is getting into the, do I ban them territory. (*sigh* I can't believe I just said that).
I really feel for a former client - 75k pages on two domains (tech manuals). Between the major search engines, he is averaging 200k views a week from the engines. Throw in rogue spiders and it jumps to 500k a week (100gig a month in bandwidth just for spiders).
The litmus test: If a search engine does more spider page views than it sends out referrals.