Banana stickers are the best. You can peel them off and stick them on someone's back and they wont't find out until later, by which point it's too late and they've already been embarrassingly mis-identified as long yellow fruit!
It's been a while since I started a painting in grayscale and then added colour later, but it's something I wanted to have another go at. It's tricky because you need to get the values right before you apply any colour, otherwise your colours will come out really funky looking, and not the good kind, either. I got a lot closer to what I was aiming for with this attempt, and it felt like a very natural way to paint as well, so I'll definitely be utilising it again in the future.
Done in Photoshop CS5