Just how ubiquitous are decoratively cut wiener sausages in Japan? Well recently, Suntory, the Japanese distributor for Pepsi, included some plastic magnets made to look like wieners (specifically ones from Nippon Ham Co.) made into cute animal shapes as giveaways with 1.5 liter bottles of Pepsi NEX (aka Pepsi Zero).
The animal sausage magnets are 2.3 cm - 3.9 cm in size (around 1 to 1.5 inches), and they come in 8 shapes: elephant, lion, octopus (with a headband), sheep, bird, seal, hippo and penguin. Each one came with instructions for making the same animal out of a real wiener.
I’m not sure if these were aimed at kids or at their kawaii-things mothers, but judging from the blog reactions in Japan they seem to have been a big hit with the mothers in any case. This blog entry  has photos of all 8 figures and how they come packaged. (The Silvania bunnies are there to demonstrate the goods.)
The figures are already showing up on Yahoo! Japan Auctions and such.
Incidentally the Nippon Ham website has a ton of wiener cutting tutorials . They are all in Japanese, but you may be able to follow the diagrams, plus there are videos. Happy wiener cutting!