Network Diagnostic Tester (NDT) -- run TCP throughput tests to a Web100-instrumented server, and detect configuration and cabling issues on your client. Java 1.4 or newer required
SmokePing -- permanent RTT ("ping") measurements to select places on the Internet, with good visualization
RIPE TTM -- tt85 (at SWITCH's PoP at ETH Zurich) and tt86 (at the University of Geneva) show one-way delays, delay variations and loss from/to SWITCH from many other networks.
IEPM-BW -- regular throughput measurements from SLAC to many hosts, including one at SWITCH