draft parts list 

1)
Basic 16×2 Character LCD – White on Black 5V
sku: LCD-00709
http://www.sparkfun.com/products/709
About $15 each
2 per student:

2)
+ USB Mini-B Cable
TBD

3)
Break Away Headers – Straight
sku: PRT-00116
http://www.sparkfun.com/products/116
About 2.50 each
5 per student
usb a-to-b cable

4)
Rotary Potentiometer – Linear  sku: COM-09288
http://www.sparkfun.com/products/9288
3 per student
~ $0.95 each

5)
Jumper Wires:
Jumper Wires Premium 12″  M/F Pack of 100
sku: PRT-09386
http://www.sparkfun.com/products/9386
Share among 3-4 Students
About $34 per pack

6)
XBee 1mW Wire Antenna
sku: WRL-08665
http://www.sparkfun.com/products/8665
1 Per Student
About $22

7)
XBee 1mW Chip Antenna
sku: WRL-08664
http://www.sparkfun.com/products/8664
1 Per Student
About $22

8)
XBee Explorer USB
sku: WRL-08687
http://www.sparkfun.com/products/8687
1 per Student
About $25

9)
XBee Explorer Dongle
sku: WRL-09819
http://www.sparkfun.com/products/9819
1 Per Student
About $25

10)
Temperature Sensor – LM335A
sku: SEN-09438
http://www.sparkfun.com/products/9438
2 per student
1.50 each

11)
Tactile Button Assortment
sku: COM-10302
http://www.sparkfun.com/products/10302
1 each student
~ $4.95

12)
From Different Supplier
XBee modules Break-out boards
http://www.solarbotics.com/products/50645/?utm_source=Google&utm_medium=Product+Search&utm_campaign=Product+Search+%28Jan11%29
2 per student
~$2.95 each

13)
2mm 10pin XBee Socket
sku: PRT-08272
http://www.sparkfun.com/products/8272
6 per student
~$1

14)
xbee Break-out Board
http://www.sparkfun.com/products/8276

(Out of Stock TBD)

15) Wire Wrap Wire  –>  30 Gauge, Digikey.com