Even if Nokia as booked 40 rooms at Ibis Hotel, this doesn't mean you can't find a cheaper accomodation too. That hotel is fine if you ca be sponsored, else I'll suggest you to give a look at http://www.hostelworld.com for example in this hostel http://www.hostelworld.com/availabil...Amsterdam/4585 you can find a room starting from 18-20€ / night. If you were going to stay more than 4 days or if you wuld come tih at least 4 people, I would suggest you to look for an apartment, it's the most cheap solution yuo can find (I payed about 25€/day with other three friend of mine 2 years ago).