I often notice presentations where images are dropped in randomly and make the slide look like the stickered door of your hostel room! I'm using a picture of our Managing Director (Sitaraman) to illustrate how this often happens. If you see the slide above, the image is a stark contrast to its background and the entire visual looks like a bit of a collage of unintegrated information. I like to usually let images blend in with the background as you see in the reworked slide below. Now all that I've done is extracted Sita from the background using the Extract filter. Now if you don't have Photoshop, you can easily a free application like GIMP to achieve the same results. This approach gives you great flexibility.
You can now reuse the same photograph in many different contexts and not have to take separate photographs to achieve the same effect. As you can see below, its now as easy to place Sita at a Train station as it is to place him in a ThoughtWorksOffice environment. Of course this requires a little more work to get into an industrial style publication, but for the purpose of a presentation/ elearning, this is good enough.
There are of course times when you can't find a hi-res picture and the image you have just pixelates way too much when you blow it up. In such cases, its difficult to integrate it with the rest of the slide and you need to make it stick out. One of things I like to do is make it look like a scrapbook or as if I push-pinned up the picture to my door or stuck it up with tape on my wall. If you think of the metaphor of putting up real pictures to show people in a group, this is exactly what you'd do, right?
Here are a few examples:
Presentation tools such as PowerPoint and Keynote usually have elements/ styles such as these built in. Alternatively, you can use an online image editing tool like Picnik to creat the right kind of effects for your images. For those of you using Powerpoint, Microsoft online has loads of add on elements such as pushpins, tape, etc to add pop to your images, so really achieving the right kind of effect for your slides isn't impossible. What you can achieve is limited only by how far you wish to go and your own creativity. Just remember the purpose of putting the image in there and remember the slide is one integrated visual - not a set of disjointed elements.