Summer Shirts on sale at Old Navy
On the homepage, click on the women's clothing icon, then "bargains" in the left-hand column, and search the tees and tanks category. Bargains abound in other departments as well, including some great deals on kids' swimwear. Their maternity line is also quite fashionable--and inexpensive. If you're expecting, check out the black tie-front swim cover-up on sale for $15.