Noises can be difficult to diagnose...lots of times they're not coming from the place they seem like they're coming from. Might have a look on
http://sheldonbrown.com/creaks.html
My personal thoughts/experiences:
- Happens only when pedaling? Check the pedals (esp. since you mention the noise is new)
- Check the crankarm bolts but also the chainring bolts.
- Does it happen when you're out of the saddle? If it only occurs when in the saddle, check the seatpost clamp bolts.
- Check the front derailleur cable end...could be hitting the crankarm (might only hit it when the derailleur is in one position or the other).