Google is now constantly tracking your searches stemming from your browser and thus your current Google searches are, unless you have disabled/removed the respective cookie, are influenced by the previous searches carried out from the same browser. For more information and how to disable all this please visit the Official Google Blog.
To get an insight about the data Google has collected about you, use the Google Dashboard Service. (Google account required; link to previous post: >>here<<) For more information about this topic please refer to The Data Liberation Front. (link to previous post: >>here<<)