Cesko,
Do you use any analysis software like Metastock or TradeStation? I am currently using Metastock and they have an average true range function that can plot it for you or you can use it in other formulas.
Keltner Channels are plotted by taking a moving average (I use a 20 period exponential) as the middle band, and plotting an upper and lower band some multiple of the ATR away from the moving average. I like to use 2.5 for the multiplier, so I have an upper band 2.5 ATRs above the 20 period EMA and a lower band 2.5 ATRs below the 20 period EMA. They are very good at containing price, usually between the middle and upper bands during an uptrend and vice versa for a downtrend. They provide significant support and resistance, and a break of these channels is usually significant. They are a good measure of volatility and will widen or shrink with changes in the ATR. I trade the S&P futures, but it should work for stocks as well.
I, too, have been looking for ways to automate as much of my trading as possible so that I can focus on getting a good entry or exit and not so much on finding setups. Metastock has helped with this quite a bit, but other software can do it as well.
Hope that helps,
Kirk