In using Google+ in noticed some in my circles were able to format text in their posts a little. I couldn't figure out how&emdash;no formatting options appeared in the editing box&emdash;but after a little searching (strangely couldn't find this in Google+ help) I found these tips...
BOLD - write text between *asterisks* to get BOLD
italics - write text between _underscores_ to get italics
strike - write text between -hyphens- to get strike