For strictly grocery shopping, traveling to work, or going from point A to point B, panniers are great. They're waterproof, easily removable so you can put them in a shopping cart, etc. The benefits are many.
But what if you need to go from point A to point B to point C to point D? I was at a cocktail party recently and I couldn't help but notice a few people who were lugging around ortlieb panniers and messenger bags. All I could think was, how convenient it would be if they could leave their panniers attached to their bicycles outside and not worry about them. The same goes for making a pit stop at the post office, pharmacy, etc. Theft is always a concern, so people are constantly carrying around panniers. [Side note: I live in Washington, DC; leaving an ortlieb pannier attached to a bike while I run into the store for 20 minutes is NOT an option].
Here's my idealistic wishful thinking: Imagine if you could conveniently LOCK panniers to the bicycle. Something requiring a key. This way you could easily remove the panniers when needed, but you'd leave the panniers on the bike at most destinations. The best of both worlds. The system should have a comfortable shoulder strap. Also, the lock should prevent thieves from unzipping/unbuckling the panniers.
I've brainstormed quite a bit about this, so below is my list of dilemmas for each of the systems I'm considering:
Panniers: Easy for thieves to steal
Donkey Boxx: Not easily removable; bulkiness gets in the way of locking to racks and carrying up stairs
Folding baskets: Not waterproof; can't leave items inside if making pit stops at stores, etc.
Bookbag: sweaty back; not available for spur of the moment shopping unless you always wear a book bag
I'm sure there's some sort of system out there for people that combine multiple short trips, but I'm just not sure what it is. Any suggestions? Thanks.