Where I keep my emergency fund?

Where I keep my emergency reserve of 6-months living expenses?

1-month of living expenses at the checking accounts at the banks of brick and mortar

2-months at the virtual banks to earn some interest

Examples

ING DIRECT
- High interest savings accounts - 4.50% APY
- Certificates of deposit - 5.25% for 9 months
- Paperless checking - 4% APY

SCHWAB BANK
- Investor checking - 4.25% APY

3-months at TREASURY DIRECT & FIDELITY where I purchase treasury bills

TREASURY DIRECT
- Treasury bills (savings bonds are for long-term savings)
- Interest rates are slightly higher and free from state and local income taxes
- Easy process to repurchase the bills automatically.
- Paperless

The money at the brokerage accounts at Fidelity (& Charles Schwab too) could be invested in Treasury bills without any fees.

I have all these accounts linked to my checking accounts at the local banks; so that most money can be available in 1 -2 business days.