An Optical Mouse

Notebooks are normally equipped with touch pads which can be
awkward. There's no substitute for the mouse. Notebooks are
predominantly used on a static, flat surface. With wireless
broadband hotspots mushrooming all over the nation's transit
locations, table tops have become as much mobile computing
desktops as surfaces on which lattes sit. The touch pads on
notebooks are also rather vulnerable to damage by static
electricity, which is a common occurrence in aircraft cabins,
carpeted airport lounges and offices and will become a big
problem when you’re on the road and lose the function of your
primary pointing device.

A good optical mouse - wired or wireless - must be able to track
movement on varying tabletop surfaces. Optical mice traditionally
had problems with glossy, transparent, or light-colored surfaces,
but technology has advanced to a level that these problems are
almost non-existent. Although wireless mice are the trend these
days, stick to a wired optical mouse by virtue that it does not
require additional power or equipment to operate; as in batteries
or receivers for wireless ones. You don't need extra equipment in
your already-overloaded and heavy notebook bag!

A Multi-Device Charger/Power Adapter

Notebooks do come with their own AC-to-DC power adapters, but
notebook owners typically carry a cell phone, PDA and digital
camera in addition to the notebook. It’s almost impossible to
carry the charging devices of all these things. Do yourself a
favor by getting a multi-device charging/power adapter. Some of
them even have the capability to simultaneously charge and power
an additional gadget or two, giving you an extra benefit of
keeping your most-used gadgets well charged up for action.

Built-In Wireless (Wifi) Connectivity Or PC Card

Notebook owners are generally mobile information warriors. It is
almost impossible to ignore the wireless revolution going around;
WiFi and soon, WiMAX Hotspots abound wherever you go. Instant
access to the Internet's unlimited resources and communicative
offerings are just a little electronic card away.

If your notebook does not have built-in WiFi, get a PC card
version which is often sold for less than $30 at computer stores.
Plugging in a WiFi PC card means you can access the Web, read and
send your emails, instant-message your colleagues/family/buddies,
broadcast your vacation video/photos or company presentations,
and retrieve company information on secure virtual private
networks anywhere, anytime you are around a hotspot, in broadband
speed.