A: 

There's ASCII 186 which is the masculine ordinal indicator, or you can use the degree sign which is ASCII 176.

Thyamine
+1  A: 

If you have a look at http://www.asciitable.com/ you see some circles in the extended ascii part. (e.g. 167, 248)

Nils Schmidt
+1  A: 

I think you could use BULLET (U+2022) and WHITE BULLET (U+25E6):

• Bullet
◦ White Bullet
Mark Byers
Win cuz you linked me right to them!
Kyle
I just noticed that you tagged ASCII. These aren't ASCII characters but Unicode characters. I hope that's OK.
Mark Byers
The kids these days call anything "ASCII" that looks like a table of characters. Ironically.
Thomas
Actually I am a kid, and I do call tables of characters ASCII. I understand the differences and things. I actually wasn't 100% that these chars. were unicode or if they were region specific by some chance.
Kyle
A: 

Beware, that the default ASCII encoding and iterpretation may change depending on the user native language.

Danvil