I have the L2 offered by iHub (advfn) but there are plenty of others that offer the service. I started with iHub since I was on the site anyways. I may eventually terminate my iHub L2 service and use one offered on a trading platform instead. I'll see this fall/winter over the next number of months. If I get serious about charts and trading and move up to use a trading platform, then I'll use the L2 that goes with it.