You used to display 12 random images and 12 from the last uploaded meta album on your index page - this is a huge resource eater. Turn those meta albums off or reduce the number of them (particularly the random images). This will safe overall CPU recources consumption.
On the displayimage.php pages (I took a look at
this page in google's cache), you have several custom objects that don't exist in default coppermine pages, so I can't tell which one might be the resource hog. I suggest turning them off alltogether (the image search form at the top as well as the bbcode and html link boxes at the bottom).
Additionally, you have a load of keywords assigned to those pics (visible in the pic info section) - retrieving them and displaying will eat resources as well - this is the HTML output generated that will populate the pic info section:
<table align="center" width="600" cellspacing="1" cellpadding="0" class="maintable">
<tr><td colspan="2" class="tableh2_compact"><b>File information</b></td></tr>
<tr><td class="tableb_compact" valign="top" >Filename:</td><td class="tableb_compact">0096.jpg</td></tr>
<tr><td class="tableb_compact" valign="top" >Album name:</td><td class="tableb_compact"><span class="alblink"><a href ="profile.php?uid=1">Infernal</a> / <a href="thumbnails.php?album=1">All Funny Images</a></span></td></tr>
<tr><td class="tableb_compact" valign="top" >Keywords:</td><td class="tableb_compact"><span class="alblink"><a href="thumbnails.php?album=search&search=Add-fun.net">Add-fun.net</a> <a href="thumbnails.php?album=search&search=Add-fun.com">Add-fun.com</a> <a href="thumbnails.php?album=search&search=BIGGEST">BIGGEST</a> <a href="thumbnails.php?album=search&search=funny">funny</a> <a href="thumbnails.php?album=search&search=pictures">pictures</a> <a href="thumbnails.php?album=search&search=site">site</a> <a href="thumbnails.php?album=search&search=on">on</a> <a href="thumbnails.php?album=search&search=earth">earth</a> <a href="thumbnails.php?album=search&search=1000">1000</a> <a href="thumbnails.php?album=search&search=Pictures">Pictures</a> <a href="thumbnails.php?album=search&search=funny">funny</a> <a href="thumbnails.php?album=search&search=hilarious">hilarious</a> <a href="thumbnails.php?album=search&search=extream">extream</a> <a href="thumbnails.php?album=search&search=incredible">incredible</a> <a href="thumbnails.php?album=search&search=shocking">shocking</a> <a href="thumbnails.php?album=search&search=briliant">briliant</a> <a href="thumbnails.php?album=search&search=Search">Search</a> <a href="thumbnails.php?album=search&search=Engine">Engine</a> <a href="thumbnails.php?album=search&search=addictivly-funny.net">addictivly-funny.net</a> <a href="thumbnails.php?album=search&search=daily">daily</a> <a href="thumbnails.php?album=search&search=updates">updates</a> <a href="thumbnails.php?album=search&search=lmao">lmao</a> <a href="thumbnails.php?album=search&search=lol">lol</a> <a href="thumbnails.php?album=search&search=fun">fun</a> <a href="thumbnails.php?album=search&search=amusement">amusement</a> <a href="thumbnails.php?album=search&search=get">get</a> <a href="thumbnails.php?album=search&search=drunk">drunk</a> <a href="thumbnails.php?album=search&search=with">with</a> <a href="thumbnails.php?album=search&search=beer">beer</a> <a href="thumbnails.php?album=search&search=steal">steal</a> <a href="thumbnails.php?album=search&search=your">your</a> <a href="thumbnails.php?album=search&search=granys">granys</a> <a href="thumbnails.php?album=search&search=clothers">clothers</a> <a href="thumbnails.php?album=search&search=geek">geek</a> <a href="thumbnails.php?album=search&search=boy">boy</a></span></td></tr>
<tr><td class="tableb_compact" valign="top" >File Size:</td><td class="tableb_compact"><span dir="ltr">57 KB</span></td></tr>
<tr><td class="tableb_compact" valign="top" >Date added:</td><td class="tableb_compact">Sep 06, 2007</td></tr>
<tr><td class="tableb_compact" valign="top" >Dimensions:</td><td class="tableb_compact">398 x 573 pixels</td></tr>
<tr><td class="tableb_compact" valign="top" >Displayed:</td><td class="tableb_compact">118 times</td></tr>
<tr><td class="tableb_compact" valign="top" >URL:</td><td class="tableb_compact"><a href="http://www.add-fun.com/gallery/displayimage.php?pos=-3118" ><b style="color:black;background-color:#ffff66">http</b>://<b style="color:black;background-color:#ffff66">www</b>.<b style="color:black;background-color:#ffff66">add</b>-<b style="color:black;background-color:#ffff66">fun</b>.<b style="color:black;background-color:#ffff66">com</b>/<b style="color:black;background-color:#ffff66">gallery</b>/<b style="color:black;background-color:#ffff66">displayimage</b>.<b style="color:black;background-color:#ffff66">php</b>?pos=-3118</a></td></tr>
<tr><td class="tableb_compact" valign="top" >Favorites:</td><td class="tableb_compact"><a href="addfav.php?pid=3118&ref=displayimage.php%3Fpos%3D-3118" >Add to Favorites</a></td></tr>
</table>
for the page
http://www.add-fun.com/gallery/displayimage.php?pos=-3118Bottom line: you have a lot of custom modifications - I'm not able to tell for sure which one causes the resource consumption without being able to see the code. Turn those modifications off.
You might as well try to keep search engine spiders from spidering displayimage.php by setting up a corresponding policy in robots.txt