Confused about my google rank

[mrgee]

I'm trying to work out my google serp for a number of sites.. I know this question has been asked before. but everyone has a different ansewr and they all lead to different results?? I have checked with a variety of tools and seem to get different results.. How can I get an accurate measure of my sites google serp
For instance I was using a chrome incognito browser window and google.com/ncr.. for some of my sites with this method they are in position 3.. But if I use rankchecker.com and the Keyword Rank Checker they are in position 8.. and likewise other test give different results again..

[goldhome]

I use Rank Tracker from link assistant. A great free tool for checking SERPs. Worth a buy.

[Tim Wallace]

keywords ranking is relative, variable slightly when you check at different time, especially your keywords ranking are out of page one, keywords ranking at first page is relatively steady in general.