|Chance are both 11 Mbps and 5.5 Mbps are faster than your internet connection so it really may not be noticable from a "surfing the web" point of view.|
If your connection rate is higher than what you're seeing between laptop and router, then it might be worth it to upgrade some hardware. Keep in mind though, where your laptop is concerned, your present interface is built into the motherboard. The only way you could replace it is if you have an unused PCMCIA slot that you could put a NIC into. If you do, and you buy a new one, you would also have to go into the BIOS on your laptop and disable the existing onboard interface to avoid conflict between the old and the new.
If you do have an available PCMCIA slot, then you have to consider, "is it really worth buying a newer/faster NIC for this old laptop?"
If you decide it's worth it, and you have an unused PCMCIA slot on your laptop, then you could look for a wireless N interface for the laptop and a wireless N router.
If it were me, I'd only consider upgrading that old laptop if your bandwidth is significantly higher than what you're getting. To be completely honest, I'd give serious thought to buying a new laptop and router.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.