I saw one in the 4 foot by 4 foot motorcycle section at the local Walmart.  I don't know anything about them either, so I can't tell you if it was a good one.  But that's a place to start, anyway.

It was black and it was leather.  I think it was priced around $25.

Got one of the Wally-world Bell bags. I think it was $26 +sales tax.   I use it to carry bungie cords, a mesh & vinyl bag (for store stops) and some other small things.  

For size estimate, it will hold four 12 oz Soda-pop / beer cans.  

On several occasions I oops's and forgot to strap it shut.  It is stiff enough that the flap stayed closed.

Only issue is that I had to put some black duct tape on the fender (my bike is black) because it was touching down on the paint and leaving marrs. I guess from fast stops.

http://www.users.fast.net/~tommack/Tmack1-LS650.jpg

Ditto for Ebay, I bought a good quality used leather bag for $10. Also, if you're looking for rear bags, check out the T-Bags close-outs here: http://www.tbags.com/closeoutsall.aspx. I bought the 8x8 Glove bag for short hops, and the TB700RKR 11x8 roll bag. Have a couple of bigger bags as well. The pocket for the sissy bar/backrest on the roll bag is kind of big, but works fine with a bungee. For $15 a piece, not a bad buy at all. They're very well made.

It's a River Road fork bag -- leather, just under 30 bucks.  I mounted it on the risers so it doesn't interfere with anything and it hides some of the cables.  Holds about what you'd expect from something it's size.  

well no luck at wally world. i thought they had everything. oh well. time to look some more

Luggage locks, one at each end, drill eyelet thru flap, front and side.

I think one fellow here used one of those skinny trailer locks for the saddle bag.

But really, a knife is a key for any soft bag.

Thanks for the ideas... I agree that a knife will unlock the bag! Is there a magnetic tank bag that you would recommend? I worry about scratching the tank but maybe that is not an issue with the newer bags.