This what you had in mind...
RewriteEngine On
Options +FollowSymlinks
RewriteCond %{HTTP_USER_AGENT} ^.*WebZIP.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Stripper.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Offline.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Copier.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Crawler.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Snagger.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Teleport.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Reaper.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Wget.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Grabber.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Sucker.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Downloader.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Siphon.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Collector.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Mag-Net.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Widow.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Snake.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*BackWeb.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*gotit.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Vacuum.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Pump.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*HMView.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*HTTrack.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*JOC.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*likse.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Memo.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*pcBrowser.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*SuperBot.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*leech.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Mirror.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Recorder.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*GrabNet.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Likse.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Navroad.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*attach.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Magnet.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Surfbot.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Bandit.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Ants.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Buddy.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Whacker.*$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^.*FileHound.*$
RewriteRule /*
http://www.imadethisupdontgohere.com [L,R]
Can't speak for it's success... just had it liying around.