Hi Augaug,
Here are some things I find indispensible when camping with my Hobie Adventure. Sometimes I feel like minimalist camping, sometimes I feel like camping like royalty.
A cot. I bring this all the time now. The wide version. It is only about 10 lbs in weight, it is easy to setup, and it sits 15" above the tent floor. It prevents you from sleeping in water if rain leaks into your tent, and you can also store lots of gear underneath, thus saving considerable space inside your tent. You end of sleeping above your gear rather than in it

And perhaps most importantly, it contributes to a great nights sleep. There is something about sleeping off the ground that contributes to a more satisfying sleep. If you want to enjoy your experience camping, you need to have a good sleep. Each day depends on it. I bungee it down on top of the Adventure's front hatch. Also, in the morning it is so much easier to sit down on the cot while putting on your clothes. So much better than lying on your back on the ground doing your best impression of an iron-cross ab workout maneuver
http://www.rei.com/product/378067I place one of these things on top of the cot. It is small, light, and easy to pack. It also has a built in hand pump. This will help keep you warm and comfortable on cool nights. I can't say enough good things about the Exped Synmat air mattress. This mattress has synthetic insulation built into it for added warmth (R value of 6!) and pumps up to its 3.5" thickness via the built in hand pump. You simply press up and down on the mattress to inflate it. Ingenious design.
http://www.amazon.com/gp/product/B001SFDJ1I/ref=oss_productI have tried sleeping in mummy bags and I find that they feel too much like what a straight-jacket might feel like - and so I just can't sleep well in them. And I find the less expensive versions are just too cold, while the pricier versions are warm - but their cost leaves me cold. This is unfortunate, because mummy bags pack up really small - which is an advantage. The sleeping bag I take for kayak camping is a 0 celcius (32 F) rectangular bag with a flannel liner. It is very roomy (I can roll around in my sleep without fear of waking wound-up like a Pillsbury apple turnover in the morning), very warm, thick and comfy, and the flannel is soft to the touch and feels good on the skin.
http://www.amazon.com/gp/product/B001M5TN6O/ref=oss_productI assume you already have a tent. I have 4 of them. This is my favourite for solo camping with the Adventure. It is a single-walled tent. Waterproof. Only two poles. Quick and easy to set up, and tiny and easy to pack. And no fly to mess around with (or lose in the wind while setting up in the middle of nowhere).
http://www.amazon.com/NEMO-Andi-Ultralight-Backpacking-Tent/dp/B003F5UNP4I also bring along a tarp just in case I get rained on. When it rains - a tarp can turn an otherwise claustrophobic "I can't believe I've been trapped in my tiny tent all day" nightmare into a "Wow - it's great to be outside watching the rain with my legs stretched out - enjoying the views while dry under this tarp". Make sure to purchase a tarp pole. Bringing some reading material for rain days might be useful too.
http://www.amazon.com/Kelty-41981003-Adjustable-Tarp-Pole/dp/B001M0NVGC/ref=sr_1_1?s=sporting-goods&ie=UTF8&qid=1300108582&sr=1-1While under the tarp, you can sit in one of these. It is very lightweight, durable, aluminum (no rust worries), mesh (doesn't collect rain and is easy to wipe off) and fits inside the front hatch of the Adventure!!!
http://www.amazon.com/Travelchair-Teddy-Aluminum-Chair-Blue/dp/B0017UYLLG/ref=sr_1_41?ie=UTF8&qid=1300109767&sr=8-41I use my ratcheting ropes that I secure my car-topped Adventure with to easily and quickly secure the camping tarp to four trees. Just pull to tighten. Simple and easy.
http://www.orsracksdirect.com/thule-855.htmlWhen the weather turns miserable a trusty weather and wind-proof lighter is a necessity. This is the one to bring if you need a reliable torch in all conditions. I never camp without it.
http://www.amazon.com/Windmill-Delta-Stormproof-Lighter-Black/dp/B0015NDPGW/ref=sr_1_1?ie=UTF8&s=sporting-goods&qid=1281717620&sr=8-1Out of all the gear I own, this is the one item I use all the time. It takes up little room, provides hands-free functionality, and shines bright for what seems like an eternity on 3 AAA batteries. It can even be used as a tent nightlight (the inside of my Nemo Andi has a little mesh sleeve near the tent peak for this very purpose).
http://www.amazon.com/Petzl-E47-PBY-Headlamp-Yellow/dp/B000N7M9PY/ref=sr_1_4?ie=UTF8&s=hi&qid=1281715588&sr=8-4Here is the saw I used to cut dead-fall. Works great. Collapses easily.
http://www.amazon.com/SVEN-SAW-Sven-Saw-21/dp/B002J900EQ/ref=sr_1_1?ie=UTF8&s=sporting-goods&qid=1300110241&sr=1-1I can go on - but I think I'll stop here. The above list includes things I can't do without.
Mike