The Macbook Air is a paragon of portability, but when not on the road many users like to use a larger keyboard, pointing device, and monitor. Twelve South sells a great stand for your Air to facilitate this, but at $US40 it can be a bit pricy for just a stand. Instead consider using a $3.49 Ikea Fantastisk napkin holder.
IKEA Hackers shares that the Fantastisk sports a clean minimalist design that fits right in with your Macbook Air. You can use it as a stand with no modifications, but the author uses an Apple sticker and four pieces of adhesive-backed foam to avoid scratching the Air's aluminium case.
This is a quintessential repurpose — a pricy accessory is replaced in both form and function with a cheap accessory designed for a completely different function. If I had a Macbook Air I'd order this tomorrow.
Macbook Air Desktop Stand [IKEA Hackers]