Well, I have some guitars, but I'm not committed enough for it really. Only know a few basic video-game tunes.
(Its partially because I need better equipment, and partially myself and my bad habits. I try to play right handed guitars even though I am left handed, I can't sit a guitar properly on my leg. I strum weirdly. I'm just not very good at it at all! XD)
I guess my main hobby is still related to gaming, which is well, customising electronics.
I bought an arcade machine quite a while ago, and I upgraded the hardware and software for it, (though it still needs a lot of work. Better buttons, joysticks, and redesigned cabinet stuff. I need some serious dosh and some manpower for it though).
I custom firmware most of the consoles I get. Mostly for the sake of it, just learning how and why it works, (though I can't get my head around the coding of it! XD), and running a few bits and pieces of homebrew.
^ Well. Thats how I started!
Now I own a Caanoo, (a nice little open-handheld. Turned it into a nice little emulation machine and music player, though since I got a slim PSP, I've stopped using it as a media player, since the Caanoo only has a maximum of 32gb of memory (Takes a SD card), and the PSP can go up to 64gb (photofast adapter + 2x 32gb Micro SDs), and I managed to get my hands on a Raspberry Pi, but I haven't tinkered with it much, as I'm waiting for the linux firmwares to be a little more stable, and the graphics chip better supported.
I plan to learn some coding and to eventually understand how to work linux, (I'm currently pretty baffled! XD).
I eventually plan to turn it into a portable emulation console (put loads of games in, hook it up to a TV via HDMI, connect a couple of controllers in the USBs. Minimum space, power consumption, but hours and hours of fun!

), but I may change my mind on its function eventually.
I want to learn to code properly, eventually, enough to make some games. My true ambition is to eventually become a Game Designer.
(I spend a lot of time coming up with ideas, though Uni has been getting in my way from truly developing these ideas. But I DO have a idea I'm beginning work on, one I could realistically do with my existing knowledge of Game Maker. Enough to create a crude prototype. But I need enough stuff down on paper first, before I begin work on that prototype)
Apart from that. I watch a little TV, browse the gaming websites on the net, talk on forums, and ocassionally watch an anime DVD I managed to find for cheap, (Netflix has some nice stuff now the UK has it).
I can read quite well, but I'm not horribly interested in books.
I am the only one at work to actually use the reading corner. Reading a mediocre book at the moment, but its entertaining enough and passes the time on my breaks.
(I used to go to a Grammer school, and I used to be really good at English literature. I only read the set books though, but I did like that stuff mostly. Lord of the Flies, Frankenstein, a little Shakespeare and Tony Harrison.)
As for music. Yeah, I listen to some of it.
Kind of have odd tastes for a 21 year old though. I like video game music. I have loads of OSTs, and I'm always whistling some tune while I'm going along.
Orchestral music I find quite pleasant, but my real favourite is Hard Rock/Metal.
Yup. I love the old style stuff.
No cookie monster vocals for me! XD
Rush, Megadeth, Iron Maiden, Hammerfall, Deep Purple, Blue Oyster Cult, Meat Loaf.
I also love comedy music. Tenacious D, Brentalfloss, Jon Lajoie, Flight of the Conchords. I like music to be fun and interesting.
None of that Drum and Bass, wubwub, R & B rubbish. Blech! :X
EDIT: Man! After reading some of other people's posts, I sound pretty boring... ;/