I got a set of servos on ebay with no mounting hardware. Is there something to use other than spending $5.00 per pack plus shipping for the rubber grommetes and eyelets?

i have used a servo screw with a washer for surface area with out grommets, never had a problem with the servo, if you wanted to you could use a couple of layers of bicycle tire patch cut to size to somewhat isolate the servo from vibration

You really need to get the proper grommets and eyelets for the servo. That "little" piece of rubber and brass is what protects your servo from failure in flight. The grommets and eyelets are designed to isolate the servo from the vibration that occurs to the airframe in flight. Without this isolation the electronics in the servo can be quickly damaged and fail. Also, the vibration can also put stress and wear on the geartrain of the servo and cause it to fail. With this in mind, the cost of the grommets and eyelets are very cheap in comparison to the cost of losing a plane. Trust me here, these are something you do not want to skimp or "make do" on.

If I remember correctly you have a Futaba radio. So going off of that approximately $10 will give you enough grommets and eyelets to do 5 servos.
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXH438&P=7]Futaba eyelets[/link]
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXH374&P=7]Futaba grommets[/link]

Ken

Awesome, thanks Ken! I knew they were important but only saw them in the accessory pack which includes servos and screws; I've got some extra servos and #2 screws are easy enough to get.

* edit what ken said Futaba grommets

Yeah, Ken is right. They really are essential to have.