Are there any freeware programs out there that will let me design Smileys, or can I get by with MSPaint? I will happily donate any new Smileys to the Straight Dope.
Welcome, Lady Eboshi.
The shareware version of Paintshop Pro is a good free resource to let you design things at a pixellar level.
By the way, the SDMB doesn’t seem to want new smileys (they always have a huge poll if they add a new one). I’ve offered to donate a barfing smiley I designed, but they didn’t take me up on the offer.
Save & Open a smiley & then practice editing it . That way you have the right size & format. The ones I use on my website are GIFs.
You could also try The Gimp… www.gimp.org I think.
I think that the Gimp would really be overkill for this. PSP is probably a better choice, and it has an interface designed for actual human beings.
Yeah, I’ve been using Photoshop for 10 years now, and I downloaded the Gimp the other day to see what it was like. WTF?!??! 
Possibly the most confusing and opaque UI on the planet.