The ideal is a t-shirt cool enough that members never want to take it off and non-members lust after it if it was even for sale.
Use some cool creative fonts, layouts and typefaces for the quotes. i.e. like Typetees.com as inspiration.
I don't want the logo on the front side just the quote so it seems a bit mysterious. And then on the backside either the logo (small) on the top center of the back or on the left shirtsleeve.
Here are some of the sample quotes -
"The way to get started is to quit talking and begin doing." - Walt Disney
"An inventor is a man who asks 'Why?' of the universe and lets nothing stand between the answer and his mind." - John Galt
"I have always lived my life by thriving on opportunity and adventure." - Sir Richard Branson
"Life's journey is not to arrive at the grave safely in a well preserved body. But rather to skid in sideways, totally worn out, with a beer in one hand, shouting "Whoo, what a ride!!" –Unknown
Our logos are available here -
I'd like to see the shirt in black or a green color to coordinate with our company colors.