Product review (5 stars): Cheap, fairly easy fix.
Our Maytag oven had been working erratically for a while.  After you set the baking temperature it would take several minutes for the burner to light, then as long as 45 minutes to pre-heat.  While the burner was on, you could hear it pulsing, (Hiss.. Hiss.. Hiss.. Hiss.. etc).  After talking with a local appliance repair man, we determined the ignitor was the problem.  The old ignitor still "worked", but it was not drawing enough current to keep the gas valve open.  The ignitor should draw at least 3 amps to open the gas valve.  Mine was drawing about 2.7 amps (measured with a clamp-type amp meter).  He said the part would cost $75-80.  I thought this seemed expensive.  [...] wanted $45 for an OEM part.  The GE ignitor seemed like it was worth a shot for $18 with shipping.  All I needed was a screwdriver to remove the old ignitor and a panel, and a pair of wire strippers to cut the plug off the old ignitor and splice it to the new.  Within 15 minutes I was finished and our oven works great.  If you have some mechanical ability, this is a definite do-it-yourself job.

3/22/2013 Update.

Over 2 years after installing this, our oven still works great!