I've been really enjoying getting into Viking re-enactment these last few years. Part of this has been to get into the combat aspects, partly the crafting and the culture. 
Part of this is collecting and using period appropriate kit, part of it is becoming comfortable using anachronistic gear. Did you know its quite hard to chug a beverage from a drinking horn unless you tilt it to one side?
I now have three viking style drinking vessels. Two traditional and one more modern.
First up is the very slick and modern Goat Mug.
The Goat Mug is a 16 oz 470mL polypropylene horn shaped take on the classic keep-cup idea. Originally a Kickstarter project, now in full commercial production. It has been a mainstay of my desk since its arrival. With its silicone ring seal screw top and drip and spill proof locking clip, it's made a prominent workplace oddity. The best part is when people ask how it stands up. The molded leather hand-cuff inverts to act as a stand to support the horn with great stability, and protects the hand from hot beverage.
The Goat Mug comes with a wrist strap and a shoulder sling for ease of carry, that clip to holes in the lid and tip respectively but I've never had much need of either. I carry mine in my hand or table it in its holder. The seals are good enough to keep in a carbonated beverage and the horn keeps my mugs of tea hot for a lot longer than a similarly sized conventionally shaped mug would. They aren't even remotely period-appropriate but are perfect for adding flair to work or the open-pit bbq pig on spit Thing in the back-yard. The curvature of the inside presents some scrubbing challenges but I'm not phased by some tannin build-up and it's dish-washer safe.
Read the kickstarter Story here.
I also have a more traditional bulls horn drinking horn. This 8oz, 250mL capacity horn ( 9oz when filled to the brim upright) natural bull horn has a fine embellished brass rim riveted on and a brass tip fixed to the pointy end. The outer surface is well polished and the insides have been well cleaned and sealed to keep the horn structurally sound after long sessions of ale. The traditional horn has the drawback of not having a stable base to sit it down so once you get started its awkward to set it down till you've emptied your horn.
I've knocked up a quick stand from some off-cuts for mine and you could always thrust it through your belt at the risk of spillage and wetting your britches. The brass fittings are handsome and lend themselves to adding some cordage as a sling. It feels nice in the hand and it has a good capacity, and certainly looks the part.
I personally like to be able to set a drinking vessel down when eating as a joint of meat on the bone can sometimes need two hands and pickled herrings are slippery.
As i mentioned earlier, when drinking from a horn, its important you tilt the point of the horn downwards or to the side, not out in front or upwards when you drink, or you'll get an unexpected surge and slosh ypur drik all over your face, in your beard and down your chest. Amusing but wasteful and wont impress that sword maiden you've been waggling eybrows at over the fire.
The final horn in my collection of drinking vessels is the "Eleet Original Viking Drinking Horn Mug"
This elegant tankard has a 20 oz capacity and is fashioned from a worked ethically sourced ox horn in which the point of the horn has been bent back to form the handle / retention grip. The base of the is a colour-matched resin to seal off the mug and the inside is sealed with a 100% food safe non-toxic lacquer on the inside, in order to avoid the real horn odor and to avoid leakage. The
exterior part is unpolished, unadorned and is kept real. The tankard feels great in the hand, it looks great and does the job.
