Distance Z Trekking Poles
Half the people I know like hiking poles. The other half don't care, but that may just be because they haven't found the right gear. I for one love hiking poles, and Black Diamond's Distance Z Trekking Poles are just right in my book. They're a huge help, especially when the length of my trek starts creeping up over 20 or 30 miles.
These poles help take the weight of your other gear off your legs and puts it onto your arms. This balance shift may feel awkward at first, but it will keep your legs fresh for the next day of adventuring. The Distance Z Trekking Poles are collapsible, so they're easy to stow away when you don't feel like using them.
I would say the only downside is that these poles are non-adjustable, so they can't be transferred well between parties. Still, they're lightweight, easy to collapse, and are incredibly sturdy. They've taken me to the bottom of the Grand Canyon, up to the highest point in the continental United States, and plenty of places in-between.