Spring/summer 2008 collections showed how important sunglasses have become. I'm sure that, as a true fashionista, you know what fashion accessories can do to improve one's personal style.

First row: Versace, Michael Kors, Gucci.
Down: Calvin Klein, Marni and Bottega Veneta.
This summer retro styles take over sports ones while oversized glasses add a bit of glam to any outfit. 50s cat-eyes (butterfly) and 60s Mod shapes (round, oval) complement chic ensembles: a shift dress, a puffy skirt, a pair of white shorts, rounded neckline tops and precious fabrics.
70s square frames add instant style to casual outfits like loose tunics or wide-leg pants, and, as well as those timeless aviators, they make a perfect team with safari style. 80s ray-ban sunglasses go well with much cooler, masculine influenced outfits or with sexy-diva, a-la-Gucci kind of looks (a short leather jacket is required). Even better if there's some sparkle going on (as in rhinestone appliqué).
Sunglass Warehouse
As I'm suffering from stylophrenia, I mean I change my style everyday (sorry, bad joke) I need more than one pair of sunglasses (and more shoes, please). Thankfully I found stylish womens sunglasses at less than $20 so I now can accessorize as my fashion-sense pleases. Yep, there are some great "bug-eye" pairs at Sunglass Warehouse; replica or no replica they look cool, are cheap and provide UVA & UVB eye-protection.

Up: Christian Lacroix, Stella McCartney, Moschino.
Second row: Diane von Furstenberg, Karl Lagerfeld and Moschino C&C.
If you like sports styles like shield sunglasses or narrow lenses team them up with modernist, minimalist looks like those seen in Calvin Klein or Marni collections. Though I would say you should bet on color-frame sunglasses, the most cheerful trend of the summer.
While white, tortoise or black frames ensure a classy look, colorful frames (red, blue, green, yellow, pink...purple, you name it) speak about an eclectic style. Think about upgraded bohemian style or modern globe-trotter and add a pair of red-frame sunglasses.
Sunglass Warehouse colored frames