I needed to get a backpack and 2 laptop bags back from uni.
On a bike.
This would've been difficult as the bike was my "crap bike", which is hard enough to cycle at the best of times, so carrying 3 bags would've been mental.
I looked around my room and saw a pile of wood, and 20 minutes later had a working pannier (shown almost complete).
I did require a small amount of gaffa, as when I set off a side fell off, but otherwise it worked well, and got all my stuff home safely.
Really heavy though...