One packing delimna I frequently face is how to carry gear during day hikes in the middle of a backpacking trip.  Most of my backpacking trips are relatively short - like 2 or 3 nights.  Many of these hikes are out-and-back type hikes - that's where you hike into a destination, like a lake, spend some time there and then hike back out the way you came.  It's usually on the out-and-back hikes that I spend a day exploring and I need a way to carry gear.  Here are a few different methods I have used...

Piggy-back daypack

A piggy-back daypack is one that is designed to attach to the back of your regular backpack.  Since I have a couple of Osprey backpacks I picked up their integrated daypack called the Daylite (shown at left). 

It's not the lightest approach but it works very well if your backpack has that feature.  The bonus of this configuration is that it gives you additional pack space (750 ci) as well as a daypack.  The downside is that it weighs over a pound.

I've used mine a number of times and it is very comfortable and packs just about the right amount of stuff.  I usually throw a jacket in there, lunch, small first-aid kit, some fishing gear and a bladder full of water.  That will fill it completely.

Ultra-lite daypack

Another option is to stuff an ultra-lite daypack inside your backpack.  I bought one of these from backpackinglight called the Gossamer Gear G6 Whisper Backpack.  This thing is huge and weighs only 3.7oz!  It has abou 1800 ci of capacity and is fairly comfortable to wear.

What I like about this option is that it doesn't take much space in your backpack when stored and it weighs almost nothing.  What I don't like is that it is too big for my normal backpacks and it makes a crinkly noise when you walk.  The noise comes from the silnylon material (like a tent rainfly).  I find that I fill it about 1/3 of the way on a normal dayhike. 

A hiking fried of mine has another, smaller, ultra-lite daypack that he uses.  It's a Dana Designs pack and is also made of silnylon.  It seems to be better constructed and doesn't make that annoying noise.  However, it also looks heavier.  My guess is that it is just short of a pound.  I searched around the Internet to try and find a link and can't find it.  It looks like Marmot bought Dana Design but didn't hook up the links from the old Dana Designs website!?  Regardless, I did find some other similar options here.

Integrated Fannypack

Another options is to get a more full-featured backpack that has a lid that can be used as a fannypack.  Several of my hiking companions do this and seem to get along just fine.  I've tried it before and found a few problems.  First, the backpacks that offer this feature are generally larger & heavier then those that don't (like 1 lb heavier).  For example, my Osprey Aether 75 (~4500 ci) has the feature but my Osprey Aether 60 (~3700 ci) doesn't.  The space in the fannypack is very limited and not very comfortable if you put too much weight in it.

Summary

Lately, if I'm not hiking in that far I take my Osprey Daylite becase of it's comfort and convenience.  If the hike in is long or otherwise strenuous then I'll take the Gossamer Gear Whisper.  Does anyone else have any recommendations?