I believe TD Waterhouse still has the sign up bonus with AA miles for a $10K deposit (or something like that).

The AAdvantage Mileage Fund, available at TD Waterhouse, earned a rate of 3.3% last month. The regular money market usually earns 0.1%-0.2% more. You can do better at a community savings bank but no miles. Also, some of these brokers charge you account inactivity fees...