One thing to mention is that you may want to utilize the PPA repositories for gearman if utilizing ubuntu. However, they do not have a maverick one at the moment.

A few things to note about the gearman client in general, if you want to unit test, you will need to create a client for it so that you can wrap the functions since "do" is a keyword :)

A last mention, is that it is a great idea to wrap it just so that you do not have so many different methods and can utilize constants between:
do
doLow
doHigh