tail of a path in Bourne

[afsipmh at cidsv01.cid.aes.doe.CA]

In the C shell if you have a variable z=/a/b/c/d then scho $z:t
will give you just d.
Is there something equally as trivial in the Bourne shell?
Basically I want to be able to get the name of a script out
of $0 without the path. This surely is a wheel that has already
been invented.
-- 
Pat Hertel                 Canadian Meteorological Centre
Analyst/Programmer         2121 N. Service Rd.        
phertel at cmc.aes.doe.ca     Dorval,Quebec             
Environment Canada         CANADA           H9P1J3