Yup, get a couple of dozen machines and install linux on them. Login/Su as Root, then issue the command: ping -f -s 65507 your.tar.get.host
The -f command under linux causes a flood of pings. It does not report the time it takes for the packet to answer back, it doesn't care. It's basically there just to flood the network with packets, in order to see where any faults may lie.
The -s 65507 part sets a packet size of 65507 bytes (the largest permitted by the ping program).
This will simulate a small ICMP on Windows-based DoS of about 25-35 machines (my estimation). If that doesn't read clear enough: a dozen linux boxes using ping -f -s 65507 is roughly equivalent to 25-35 windows boxes using ping -l 65500 -t -w 0
Other than that, there's nothing really easy to do it with.
