1. Go to the list and choose Settings | List Settings
2. Click "Advanced settings"
3. Change the first entry, "Allow management of content types?" to Yes
4. In the “Content Types” section that has just appeared, click the "Item" link
5. Click the "Title" field and select “Hidden (will not appear on forms)”
6. Change the management of content types back to “No” (steps 1-2)