Recently posted onto Wolfram's Blog is a set of 10 tips for how to write fast Mathematica code.  It is a very amusing read -- go read it now, because below I am going to make some comments on it, assuming that you have read it.

1. Use floating-point numbers if you can, and use them early.
   Basically: if you're using Mathematica as a...

If you want to know what ::uneval does (it's an advanced option for procedure parameters), you can look at the uneval section of ?parameter_modifiers.  It is useful when you want to write a function which works on raw user input rather than on evaluated input.  This is quite tricky, and fraught with danger, and should only be used as a last resort;  but sometimes it really is rather handy.

This is a follow-up to a rather old posting about maple.vim.  There is now a maplevim project on google code to helpfully get the community to work on upgrading maple.vim a bit more frequently. 

Right now there is a shipping version of maple.vim checked-in, as well as a set of 'pieces' (in the pieces sub-directory...

Here is a challenge: reproduce this Mathematica notebook in Maple - without cheating, naturally.

I think I'm jealous.  But I'd love to be shown wrong and have someone do up a Maple 14 document which does everything that that notebook does, only better.

Users with high enough reputation on MathOverflow get increasing amounts of power on the site.  Generally, it works rather well.