With names like “Strawnana Berry,” “P-Nut Power Shake” and “Mahalo Mango” — my personal favorite flavor — a little bit of embarrassment has always been a part of ordering a $5+ Robeks smoothie. But today from 3 to 6 p.m., declare your flavor with pride at D.C.-area Robeks and treat yourself to a 12 oz smoothie for $1. Expect long lines as people wait for their daily serving of fruits in smoothie form. There are…