Well, the posting on the Forum has already had its first response, and some very useful information there too - thanks Rupert !
You are going to need to do some researches of your own soon, and there are some very useful websites being thrown up by looking at past 'threads' on the Forum.

http://www.natureview.nl/spits/ - produced by Arjen Drost - try the links page for more detail
http://www.svalbardbutikken.no/index.php?action=3 - the English page of the Svalbard Co-Op: the main supermarket
Notice that alcohol sales don't have the same hours as sales of other goods:
Sales of alcohol
Monday-Friday: 10:00-18:00
Saturday: 10:00-15:00
Sunday: Closed
Can you think of possible reasons for that ?
The Co Op site also offers a rather useful PDF download of a map of Longyearbyen.

http://www.spitzbergen.de/HTML-Dateien/E_Index.htm
The English version of Rolf Stange's page

And a picture clue to finish...
What are these "golf balls" in the snow for ? (Answer next week...)