have some of these:
www.mail-archive.com/[email protected]/msg00418.html

I've seen one before which had nice looking ways of saying rather nasty things, but cant remember where, or find it on google.

My personal favourite was a story my father told me, where a useless employee was going off to a direct rival who were bidding for the same contract as my dad's company. the reference read "I hope you enjoy having him work for you as much as we did".

Staying moderately on topic though, try some of the following:
"regularly exercises his keen wit"
"has obviously picked up much vocabulary from his parents"
"it is a joy to see him working"
"would benefit from a more hands-on teaching style" (i.e. needs a slap)
( Tedium Alduce me to interlow myself., Tue 9 Jun 2009, 21:15, Reply)