Getting ready for class soon and need to replace my aging (7 years) Compaq.

What type of computer do you guys flying the line tote around (tablet, netbook, small notebook)? Is battery life something I should strongly consider? In school is there a need for a disk drive? Once I'm on the line, are company updates etc on flash drives, downloaded, or disks (do I need a disk drive)?

A virtual beer for guidance and input will be rewarded :-)