I echo the endorsement of DVD player cases.
I went shopping today (Richmond, VA, USA) for a case at four stores: Wal-Mart, Staples Office Supply, Circuit City, and Best Buy. Oh, a fifth, a Christian Book Store (A large Bible case is just about the right size).
The least expensive was a "DVD Player Sleeve" at Circuit City, $10 US. It had neither a handle nor any auxiliary storage pockets, so I decided not to buy it.
Most interesting was the range at Best Buy. If you went to the Macbook Accessories area, you could get a reasonable case for $90. Near the Windows laptops were a few smallish cases, for $30 - $50. But at the portable DVD player department was a very nice selection, all nicely padded, including a simple lightweight neoprene foam case for $20, and a very full-featured (lots of pockets) padded cloth case for $30.
I think that DVD players are assumed to be used by children, so their cases are priced lower than stuff that's targeted at netbook owners, and much lower than Macintosh owners.
I chose the lightweight neoprene one, which has a handle, shoulder strap, and a couple of thin pockets (just big enough for the power supply). It's the init (brand) 10.4" portable DVD player sleeve. If I find myself hauling a lot of Other Stuff with my A1, I might go back and get a larger case, but for now, this one feels right.
-Tom Williams