If your male, and you're a wildcamper or just a lazy git then you will likely well versed and already have a designated 32oz/1 ltr Wide Mouthed Nalgene Bottle for 'special personal use'.

There is a reason why mine is green as opposed to my other one which is blue... one that I actually drink from.

On a recent camp trip my friend and fellow nalgene user brought along a pack of fishing line mini glow sticks with the mind of sticking them on the tent guy lines.

After a few beers one of these ended up in a Nalgene bottle and an light bulb went on in our heads... admittidly a pee green red swirling glowing light bulb. Combining said bottle with a mini glowstick makes for a brilliant idea. You can see where the bottle is in the dark* when it is needed most, you can observe the ratio between the rapidly rising fluid level and inserted flesh and thus make adjustments accordingly, you can watch the glow stick swirl around in a hypnotic fashion (in-pee entertainment), and when your done you got a DIY bottle lamp that will last the rest of night**.

Ray Mears never gives good tips like this.

*The author admits only backwood greenhorns and tenderfoots wouldn't know where there pee bottle was located in the dark.
** That is if your other half doesn't take it to use as a hot water bottle.