Yes, you can insert a bullet. It's not a Photoshop thing, though - its a Windows thing. Because of this, you can insert it anywhere (not just Photoshop). Hold down ALT and while you're holding that press 0149 on the keypad. Its important that you do it on the keypad and not on the numbers above. Once you do that, you'll get •
Keep in mind that some fonts don't have a bullet in the character set, so you might have to use a system font like Arial or something for the bullet and your custom fonts for other text. As another side note, if you go to Start > Programs > Accessories > System Tools > Character Map
you can see all the fun characters and combinations you can make.