You could also use a CMOS 555 timer (ICM7555) as a monostable driving a p-channel
high-side power switch?
Something like the circuit on this page, but drive the gate of a logic-level p-channel MOSFET
instead of a buzzer, and set the time constant for 1/10 second or so:
http://www.technologystudent.com/elec1/5554.htm
The 7555 is far superior to the 555 in terms of decoupling requirements
and supply range and power drain, BTW, I prefer it.