Word War combines Boggle and a word finder in an addicting intellectual game. It also has the longest registration of any of these games I've seen.

<a href="http://www.kprobe.com/kprobe/iPhone/ww.php"><img src="http://www.modmyi.com/appimages/wordwar.png" /></a>

<a href="http://www.kprobe.com/kprobe/iPhone/ww.php">http://www.kprobe.com/kprobe/iPhone/ww.php</a>