These days, I have a crush on making personalized board books. You can buy blank board books from a number of online stores, but I prefer Blank Slate. Not only do you get four great blank books, they also send you appropriate sized labels and a cd with templates to use. Just use the template to add text and pictures to the labels, print, and stick to the page. Super easy, and it looks great.
If you don't want the labels and just want the books, you can try Romp in Brooklyn. Their books come in two sizes, but I've found they are frequently out of stock (it's a popular item) (and Romp is kind of an awesome store, by the way, very worthy of checking out).
So far I've made a birth story book for Oscar and two black and white infant books - one for us, and one for a friend. The black and white book is the only book I can get Oscar to focus on. He stares at every page.
For the Black and White book, I drew images in Microsoft Paint and used some basic shapes from Microsoft Word. If you try this out for yourself, here's a tip: to improve the look of images you draw in MS Paint, use Vector Magic. It is a free program online that converts bitmap images into vector images - in my non-techie understanding, it basically cleans up and smooths out all the nasty jagged edges that tend to show up in MS paint drawings.
Click here for a template with my black and white book images, if you want to make your own: Black and White Book Images. They are sized for labels that fit four to a page. (Thanks, LiEr, for showing me how to do this!)