Trackpads and the classic notebook nubbin are fine for the odd dally with your laptop, but if you're travelling around and still need to work then a decent travel mouse is a bit of a necessity.
Genius' Traveler 915 is a wireless laser mouse designed specifically for that purpose, and well-designed it most definitely is.
The killer selling point of the 915 is the tidy little drawer in the base of the mouse which houses the wireless dongle when not in use. Call me a foolish muppet if you will, but I'm forever losing these tiny wireless receivers and as such I'll tend to plump for the wired alternatives, so this neat little solution is a godsend for me.
It's a very low profile mouse, so it's not particularly comfortable for long-term use, but this also means it can be stowed away easily in your laptop bag without any unsightly, hip-bumping bulges.
The 915 is well made, excellently designed, surprisingly responsive and reassuringly weighty too.