I never thought that I'd need one of these, but since I get asked the same questions a lot lately, I'll just post my answers here for easy reference (it may be updated as needed). Please don't think of me as rude if I just refer you to this F.A.Q. instead of answering you directly.
Q1: Do you take requests?
No. I have taken requests in the past, but only of things that were interesting to me - and not to sound mean, but making sprites of random OCs for random people is not very high on my list of priorities. If I start accepting requests in the future, I'll make an announcement on my profile, and it will probably be limited in some way.
Q2: What about commissions / art-trades?
As for art-trades, well, it doesn't hurt to ask. It really depends on my mood and the amount of free time I have, though. Just send me a note.
Q3: Where can I download the program / your ponies for the program?
Most of my ponies are either already included with the current versions of the program if they are canon (meaning they appeared in the show) or separately in my thread in the Desktop Ponies forum. If one of my sprites isn't available as a desktop pony, it's either because I didn't finish the entire spriteset yet or I didn't intend to make it into a full desktop pony for whatever reason.
Anyway, you can find the Desktop Ponies forum here (bandwidth is kinda limited, so if the link doesn't work, try again the next day).
You can also visit the Desktop Ponies group on deviantArt here for more info (and even more ponies):
Q4: May I use your sprites?
Well, if you want to use my desktop pony sprites as an avatar or in your game projects I'm generally okay with this as long as you give credit (and preferably link back). Just don't claim them as your own or make money of them (and yes, DA points count as money).
This does not include simply uploading them to your gallery or making bases of my original animations.
Also, keep in mind that I didn't create my sprites with deviantArt-avatars in mind, so most of them would need some cropping/resizing to use them as such. Please don't ask me to do this for you.
Q5: Can you post (insert pony sprite) facing left?
I don't know why, but I get this question a lot.
Usually, I don't bother posting sprites for both directions, simply because for the most part they are the same sprites, just mirrored. But even when they are different from each other, the difference is usually subtle and it doesn't really feel necessary for me to post both versions.
If you really want to look at my sprites facing left, my full Desktop Ponies have them usually for both directions (see Q3).
Q6: How do you make those sprites?
Well, I draw all my sprites in Paint Shop Pro 5 (but pretty much any picture editing program will do, preferably one that supports layers) and make the animated gifs with MS Gif Animator (which is simple but easy to use and can be downloaded for free). I also made a simple tutorial for a basic trotting animation which you can find here.