If there's a demand, maybe someone should set up a swap that specifically states that it's OK if the blocks smell of smoke or have pet hair on them?
I did a birthday block swap last year. It was fun, but I'm not planning to do it again. I just don't have the money, for starters. In the UK, quilting fabric generally costs about £10/m and international postage costs (everyone else was abroad) are high, even if you try to send batches of blocks to someone to redistribute every few months. The main problem, however, was that my birthday is mid December and a lot of the participants had stopped bothering by then. I really had to beg to get remotely near the number of blocks I'd sent out, and only got them because some kind people who weren't even in the swap made "angel blocks" (one person made five, bless her).
So it was interesting and fun as a one-off, but too many problems to want to do it again, even though it's supposedly better-organised this year (after the one person who said her birthday was in Feb and got an awful lot of blocks before we realised that she'd scammed us and not made a single block for anyone else). I asked for crazy quilt blocks with a female sexuality theme (one person took this fairly literally!), you know, the shape in the middle and the colours and such. I've just started sewing the blocks to the sashing tonight, it's shades of red and deep pink and orange and the back will be red. I'm really looking forward to the quilting: appropriate motifs (I don't think I'll dare post the quilt here, judging by the zombie quilt people will be too shocked by it!) and it'll be my first foray into big stitch quilting with perle 8. The quilt is going to this charity:
http://www.forwarduk.org.uk/, it's a subject I feel passionately about.