I have an Incase Travel Kit Plus and love it. Only downside is that it doesn't have a shoulder strap so I wind up carrying it around in my hand. Whereupon I look like I'm carrying a bible and about to knock on your door. Any other options?
BestBuy has a netbook sleeve by Swissgear that has a pocket for the ipad, an additional pocket large enough for the Apple BT keyboard, 2 outer pockets which store foldaway handles as well as miscellaneous small items such as the wall charger and it comes with a strap.
I think it was around $30 or so when i got it.
Have a look at Tom Bihn Messenger Bags, more precisely Ristretto for iPad. Slightly expensive but the quality is very good with lifetime warranty.
http://www.tombihn.com/page/001/PROD/200/TB0222
There is also a good review on Youtube of this bag.