A picture from digital camera contain data we often don’t need it, and usually has big resolution – all make the picture heavy. For uploading in blogs and sending through email it will need much effort and time.
There are many small free software to make it light, and my favorite is PIXresizer from Bluefive Software, http://bluefive.pair.com/pixresizer.htm
The interface is such simple and easy to handle, it has no advertisement, but fulfil what we need. It doesn’t support all format but for the most common ones. It works also for batch files in an few clicks.
You can go to the website to download and try it.