if you literally want no risk you should look at a savings account. You don't say which country you're in so this may be irrelevant but I have one with ING Direct which offers a high rate (5%ish). A cash ISA is another alternative. Depends on how long you think you'll leave it there. www.fool.co.uk is a great site for financial advice
Look at Treasury Bills as opposed to bonds. Typically 91 day US treasury bills can be bought online paying about 1.61% a quater. Compounding results in about 7% depending on interest rates. The UK offers similar investments and all will have their own tax regimes. If a US account and a debit card, no tax. Not sure about the UK. See:
http://www.treasurydirect.gov/
P.s. These are 99.9% safe. Japan invests 1.5 trillion in this!