Text help?

Hello - this is my first time here, and it's nice to meet you all.

I have noticed that some icons here and there have this sort of  "highlighter" effect on them -

e.g. (belongs to oui_je_danse )

However... I have tried looking for a "highlighter" tool on both Photoshop CS3 AND on Photoshop Elements 6.0 and I can't find it. I would really like to know how to do this, as it looks like a nice effect and a good way to get text to show up.

Thanks in advance to anyone who can help!