I usually do this by hand if I need to do it just once. It's not that difficult.
If you're interested in custom import like on semi-daily basis, let me know, I have written a sort of a converter in PHP, I can share it if you can pay my time. My import creates a category structure based on fields in csv file.
QC 3.3 EXT should have some kind of import/export too, I think that it works only with products, though and doesn't support product 'features'. http://opensolution.org/os/templates/en_Quick.Cart_features_3.3.html#import-export
beholder - yes it support some of product features. list of fields: name, price, price discount 1, price discount 2, old price, position, status, weight, stock level, product's availability, keywords for searchbox, site title, meta description, meta keywords, short description, full description, pages connected with product, product ID
