Technically to draw more than 100ma the port must request it from the host, at least according to USB specs, this doesn't stop it from drawing more current but some hosts may shut down the port if more than 100ma is drawn, depends entirely on the host implementation. You do need to terminate the data lines on some phone's but it's phone dependent, not sure how it's done, probably just a resistor, Google should find you the info you need.
You don't just need a charger circuit though you need a regulator circuit for the output, because a phone won't charge straight from a Lithium source, the voltage needs to be higher, most cell phone's use 4.6-5.0 volts so you need a boost converter.