As shilolo said, if by “secure” you mean insured against bank failure, then yes—insured by FDIC up to $100,000.
The reason for the difference in interest rates has to do with bank cost—ING only has 6 physical locations in the US, compared to a typical bank, which would have hundreds or thousands. There are many virtual banks, ING is the largest. You might want to check out SavingsAccounts.com—it seems to have a pretty comprehensive list of the different banks and their rates. You’ll, of course, want to do a little research on a bank you consider—ensure it has FDIC insurance, and has a good record.