If your wife has the required number of PRSI contributions from previous employment, she may be entitled to Jobseeker's Benefit which is PRSI-contribution based.
The current requirements are -
52 weeks PRSI paid since starting work
and
39 weeks PRSI paid or credited in 2006 or
26 weeks PRSI paid in 2006 and 26 weeks PRSI paid in 2005.
(these will change from January 2009).
If she doesn't have sufficient PRSI contributions, she can apply for Jobseeker's Allowance. JA is means-tested, so your income will be taken into account in determining any entitlement.