haha, good idea. interested to see what you can make of that.
sorry people.. i'm going to hijack this thread for a moment to answer Eldest Dragon's question.
ahem..
practise = perfect.
no.. scratch that,. practise*7029 + 564(practise) = perfect.
but i'm glad now that i did put all that practise in. knowing anatomy off by heart and being able to modify your pics by just seeing whats wrong with them at first glance.. its a blessing.
i had to practise so much to get anatomy right, see pic.
http://i2.photobucket.com/albums/y10/Treborguy/sneak2.gif
but you can even see there that i couldn't get the legs the right length.
tips
1) buy a wacom tablet (£19.99) and a scanner (more expensive

).
2) draw your concepts out first in pencil, rub anything out that doesn't look right. yes, rub it all out and do it again, don't be afraid to go over your lines, no-one gets all the lines right in the first stroke.
here, i've done a quick batman drawing for you, with a big head.. yeah.
BATMAN! nananananananananananananananana BATMAN!!
http://i2.photobucket.com/albums/y10/Treborguy/img060.png
see how scrappy i've been with the lines? try it, it's just a rough after all.
3) references - get plenty of them, it's not wise to attempt anatomy, or the face with out a reference unless your really confident.
4) Scrapping work - it's hard to deal with, but if you've spent half an hour trying to get a leg right, take it as a sign, do your character in a slightly different pose.
5) step back from your work - after staring at a piece for ages, the mistakes on the piece kind of blend in with everything else, and you start to think that it's right. so just literally get up and step 2 meters back, compare your piece with your references. ask yourself, are the legs too long? is the face some sort of pentagonal or squiffy torus shape, somehow?
6) liquify on photoshop - the best quick correction tool i ever came across when doing line art, expand bits of your drawing, shift them over to the left a few centimeters, whatever. sure, its messy and blurry, but for quick concepts that no-one else has to see it's perfect.
7) the internet! - submit your work for scrutiny. and if everyone tells you it's sh*t then count it as a blessing! you'll learn far more from failing than you will from accidentally getting it right.
8) be inspired - if you want to go further with drawing, look at art forums like cgtalk.com and bask in the work of the artists over there, aim for higher things instead of doing what you 'think your probably capable of'.
9) PRACTISE!!