Fidelity has recently overhauled its international trading service to the point where it may be relatively useful. Previously, you needed a minimum balance of US$25,000 and over 120 trades per year or a balance of US$1,000,000, which made it extremely uncompetitive since any investor who met those conditions could do better elsewhere.
But with the international trading service now open to all account sizes, a large number of new markets added and reasonable fees for online trades in most, it now seems to be one of the most competitive providers available to US investors, at least in terms of range (Interactive Brokers is considerably cheaper, but covers fewer markets). However, be aware of the usual excessive FX conversion fee (up to 1%) – investors should try to work around this as much as possible by avoiding changing currencies within the account too frequently.