Melbourne commuter cyclist woowoowoo has opined that a bike basket is an effective theft deterrent—what self-respecting bike thief is going to pinch a bike with a daggy basket dangling off the handlebars?
Of course, baskets are also useful for carrying stuff, and it's to that end that some local cyclists have hacked up some handy rack-top baskets.
The standard is the good ol' milk crate—simply add a bungy strap and you're away:
But how about this innovation? The supermarket basket firmly mounted with a length of rope (which was probably hanging around in the shed or in the back of a cupboard) has the advantage of being a narrower and lower profile, and has a flatter bottom that sits nicely on the rack:
Of course, some people take their hacks a bit more seriously, showing signs of true craftsmanship. As a case-in-point, take this adjusted milk crate held firmly in place by some metal hose clamps. Note the trimmed front (presumably to eliminate butt-rub) and the edges rolled over with some lengths of garden hose. Nice work: