The Tourist site of Eindhoven links to several hotels and bed and breakfast places.In particular, this page lists some cheaper options.
We checked with a few bed-and-breakfast places but they are all rather small and thus reluctant to make block reseravations.
Some places offer better deals for double rooms. If you are interested in sharing a room with some other summer school participant please send an email to tanja@hyperelliptic.org and we will try to match you. When you mail us in this context you accept that we pass your email address to possible room mates who will then contact you directly. Please mention your sex so that we can match you appropriately!