Found a 1941-S nickel from the good old U.S. of A. which has little extra value but in the Red Book it does have a footnote.
Apparently both a large and small mintmark exist. Basically the mint made letter punches of different sizes but slowly throughout the years the settled on a standard size. The first standard was a small size lettering but then they moved to a slightly larger one.
By 1941 the San Fransisco mint changed over to the larger S for it's coin but some of them had already been struck with the older small S. Allegedly only 10 dies were punched with the larger S making it more scarce but at the end they are of equal value in low grades.
With only one 1941-S coin in hand I have nothing to compare it with. So I stopped by The Lincoln Cent Resource which has great information on just this topic. The great part about government standards is that they generally carry over to other coins. So reading a few forum post I can safely say that the pictures of the Lincoln cent variety are the same for the nickels.
Image source: http://www.lincolncentresource.com/San_Fransisco_Mintmark_Styles.html
So looking at a close up of mine I see the notches at the serif (sometimes called Trumpet Tail). Also it is more square not as curvy-round.
I must conclude it is a small variety, then again from what I read there are sub-varieties.
So until I get my hands on a second 1941-S, I'm sure I have a few but I'm too busy to look now, I will say with 90% certainty this is a small.
Here's the stats...
Type/Country: 5 Cents / United States of America
Year: 1941-S (small mintmark)
Metal: 75% copper 25% nickel
Do you have an older nickel and want to find out its value? Leave a comment and I will do my best to find out the price and history for you.