Unless there is an iron clad connection between your business / product and the domain name with an "s" ... no.
It can be easily argued that is the domain is used to confusing and mislead and thus could be taken away from you... especially if the domain without the "s" is trademarked or very well established.
I would also say NO, don`t do it. There have been lawsuits about cyber squatters who by domains and hold them to make the rightful owner (or person who should own it) pay more.
For instance...I purchase a domain name britneyspears.com. What happens when Britney Spears wants the domain name as it’s her name? My name is clearly Gerald...do I have a right to the domain name britneyspears.com even though I buy it? Not in some cases.
Also, take for instance Microsoft.com there was a underground website called mikerosoft.com that supplied pirated software. What do you think happened to them when Microsoft found out about this domain name and what they were doing?
Say I ran a site called googles.com. People will always remember google.com vs google.com as its name is out there and even though my site is totally different, people always leave off the S.
That is just my two cents...I would go with a NO also.