There are plenty of powerful pieces of software for doing highly impressive things with your images, but sometimes you just need a specific tool to perform a job as quickly as possible. Here are my favourite 5 websites for those last-minute photo tasks:

Aspect Ratio Calculator
Great if you need to resize an image whilst keeping it in the correct proportions. Simply enter the width and height and then choose your desired new width or height to find out what the other measurement should be.

PicResize
Quickly crop and resize a picture and then save it as a JPG, GIF, PNG or BMP.

PicMarkr
Add a text watermark, image watermark or tiled watermark to a photo or batch of photos. You can import from your computer, Flickr, Facebook or Picasa.

ExifViewer
View image metadata including camera details, timestamp, exposure, aperture, focal length, ISO, resolution and white balance.

Filemail
Send a large photo by email quickly and easily with no need to create an account.