Suggestions for recruitment ?

[bossref]

BOSS Officials in San Diego is always in need of
new refs for January through May and July-August.
We've been recruiting by word of mouth, local newspaper
public service announcements, posting fliers in gyms,
and even offering $$ incentives to current officials.
Anybody have other suggestions?
We are considering contacting the colleges, JCs, and even
some high schools, or holding regional recruiting clinics.
PS I don't mind creative suggestions. Thanks.