[Al Skierkiewicz]

I think it is important at this point to remind everyone, that adding weight needs to be done in a manner that will not cause damage to the field or other robots. For that reason simply using tywraps to hold practice weights or lead blocks in place is not recommended. Use something much more reliable like a threaded fastener. Lead, if used, should be sealed or painted to minimize contamination and as Russ pointed out earlier, should not be machined in the pits.
From the pneumatics even if you don't use the system, the compressor and air tanks as well as actuators can be used as ballast using their normal mounting hardware.
R71> In addition to the items included in the Kit Of Parts, pneumatic system items specifically permitted on 2009 FRC ROBOTS include the following items. All included items must be“off the shelf” pneumatic devices rated by their manufacturers for pressure of at least 125psi, and used in their original, unaltered condition (except as required for assembly with other
components).
A. One or two additional Clippard air storage tanks (Clippard Part Number AVT-32-16), equivalent to those provided in the kit. This means that up to four, and no more, Clippard air storage tanks can be used on the ROBOT.
Lengths of heavy gauge wire can also be used and easily secured with wire ties. #4 or even #0 can be a way to distribute weight easily while increasing the robot weight.
I once had a team mount up a bench vise and another team mounted a toolbox to compensate for the loss of an arm or ramp that they decided was causing more harm than good. Both used heavy, threaded fasteners and of course fell under the COTS parts and cost basis sections of Robot Rules.