I tried really hard to show people this trick. I think it deserves more views (so please share!). Basically if you want a really good looking document that also compresses as PDF to a very little files size, you shouldn’t create minimal resolution images with very little compression, you should actually create large high res images and compress the bejesus out of them!
So the trick is (but you should check out the video if you can make time):
To compress PDF’s well, don use small images with minimal compression, instead use large (file size) images with lots of compression. The sheer amount of pixels will hide the image compression and give you a really small file that still looks amazingly sharp. Go head, try it out!