If you are receiving a lot of buyers through your home but aren't receiving offers, then it is either priced too high or shows poorly. In this market, orice is the driving force. If you have receive offers, but they have been low-ball offers, then maybe you should look at the price. It's impossible to say when you should consider reducing your price without knowing all the circumstances, but if you haven't received an offer in 30 days, it's time to re-evaluate your price.
I just attended meeting of all the mortgage officers for one of the larger regional banks, and their treasurer and ecomomist was finding home prices dropping at 1-2% per month, and expected it to continue through this year. While I think this is a pessermistic outlook, what it could mean to you is that for every month your home sits on the market, it is worth 1-2% less. If you have a $400,000 home and it doesn't sell in 2 months, it could be worth $16,000 less. So even if you dropped the price by $10,000 you are still behind the eightball. You could be playing catch-up with the market for months.
An example of this is someone I know who was selling a condo in Florida (be glad you are not trying to sell there). They placed their property on the market in 2005 at just above what others had recently sold for (at the height of the market). Other units came on priced lower, and sold. They lowered their price to that level, but now the market had dropped even more. This scenario went on for 2 years until they dropped the price fast enough to catch up with the market. The bottom line - they originally listed their condo at $280,000 when they could have sold it for $250,000. Instead they played the waiting game and ending up selling for $140,000! This is an extreme example in a market that is much worst then we have here on the North Shore of Massachusetts (we actually have it pretty good for the most part)., but I have seen this same thing happen locally.
If you home is not selling, there is only one reason - marketing... and pricing your home correctly is an intergral part of marketing. Determining the correct price in a declining market isn't easy, though. But if your home is not getting many showings, or a lot of showings without offers, drop the price quickly if you are really serious about selling.