I just bought the Intro-Tech Automotive Windshield Sun Shade, Part. no. HD-50 for my 2009 Fit Sport. It fits great, works great, and you can stow it out of sight under the rear seats (behind the seat support bars.) Just roll it up fairly tight, put the velcro strap around it, lift up the driver's side rear seat and slide it behind the passenger side seat support, then let the seat back down.
I bought mine from AutoAnything.com for $39.95. It came in the mail 6 days after I placed the order.

 

Rex, thanks for the info... those of us with baby car seats on the rear (2 of them!) are out of luck..

 

Out here in broiling hot, sun-filled Arizona I've used these twist & fold "spring" sunshades for years and, amazingly found one just the right size for that huge expanse of windshield in my new 2010 Fit. Another great feature is that a twist-of-the-wrist-and-fold easily gets it down to a size which allows inserting it right into the driver's side-door pocket. How convenient is that?

You might want to check it out yourself on Amazon.com:

Amazon.com: Type S SS12501-24/12 Silver Spring Shade: Automotive

 

Thanks philyc! I've been waiting for something like this... ordered mine just now. Good price too!

 

Reporting back... I purchased the sunshade philyc suggested, it is PERFECT for the 2009-2010 Honda Fit!!! The thing is really HUGE, and covers the entire windshield! It folds to a rather small 'circle', which fits in the seat pockets facing the rear row...

AWESOME! And VERY CHEAP!!!

 

Just wanted to add, I purchased this super jumbo sunshade from Amazon for $13 and it's large enough to cover the expanse of glass that is the front windshield. The measurements are 31x38. (photo included in the Amazon product page)
You do need to use the visors to keep it up and due to positioning, the rear view mirror will be covered as well.

I preferred this model with the two individual pieces over the one linked by philyc b/c its easier for me to fold.

A similar one can also be found at walmart for a few dollars less.

 

Where did you get this?

 

A Disney Cars Sunshade...the one on EBay is too small for our Fits...
Disney cars car front sun shade | eBay

Here is the Amazon Custom Sunshade-$33.95 ($5.95 Shipping)
Amazon.com: Sunshade for HONDA FIT 2009 2010 2011 Heatshield Windshield Custom-fit Sunshade: Automotive

Heat Shield Sunshade-$34.95 ($12.49 Shipping)
Custom Windshield HeatShield for the 2009-11 Honda Fit

Handa Accessories-$29.95 ($9.49 Shipping)
Buy Honda Fit Accessories - Discount Genuine Honda Accessories

CoverKing-$26.99 ($22.99 Shipping)
Honda Fit Coverking Custom Sunshield by Coverking Accessories

CoverCraft-$39.99 ($10. Shipping)
Covercraft Car Covers and Truck Covers Custom Made or Ready Fit

 

It is a Heatshield sunshade and it covers the two small front windows also.