Princess Modest Swimwear is a website I only got acquainted with recently, when their representative contacted me and offered a 10% discount for my readers. The brand is Israeli but ships worldwide, and I'm always in favor of supporting Israeli businesses. To activate the discount, simply type 20010 as coupon code when ordering. PS: the coupon is valid until December 31, 2011.
Now, personally I'm not sure I would feel comfortable swimming at a mixed beach or swimming pool even fully dressed, because even modest swimsuits are bound to cling a lot when they are wet, and at women-only beaches or pools I'm OK with wearing a simple one-piece swimsuit and my husband's swimming shorts. But modest bathing suits such as these have the additional bonus of sun protection, which is important in Israel. I would also wear something like this, I think, if I had a private swimming pool in my garden.
Anyway, it looks a lot better than what you can find in most standard stores.