Many manufactures offers a free samples of their electronics tools. To get some you need just fill right form and you will get free sample. For companies it great marketing job, for us – great way to get some nice electronics elements.
Here you can find a list of producers that send free samples of their products.
maxim & dallas **broken link removed**
semiconductor corp. **broken link removed** - central
fairchild semi http://www.fairchildsemi.com/samples/index.jsp - www.ti.com
Texas Instruments -> http://www.ti.com/
Maxim - Dallas Semiconductors -> **broken link removed**
Sometimes you need to contact by e-mail. But be careful because some of them doesn’t work with generic addresses. Best option is to send e-mail from your school address.
Of course you wan’t get too much samples at once. It’s because free samples chips are for hobbies not for business.