On Google+ you can make a really great impression with the images you use, especially when they are original/different.
Alongside your 'profile picture' your Google Plus cover photo is very important to consider.
Just like in the real world, first impressions count and here is your chance to make an amazing impression.
In the two interviews below we will look at two different angles; from there you can decide to which one your relate best.
Size of the cover photo
The optimal size is 2120 x 1192, but if you add an image then got to edit it in Picassa (i.e. the programme within Google+) then you can choose to select and area and 'crop'. This will make it smaller. Note: if you do this, it may 'mess' with how everything is displayed across devices.
Approaching your images from a marketing perspective
In this interview I talk with Stephan Hovnanian about the canvas in the Plus called your cover photo. We discuss sizes, devices and platforms and then Stephan gives us all a very simple tip to make sure we are optimizing our cover photo for SEO. Short and sweet - one to watch for sure!
Approaching your images from a design perspective
Below is another great interview with a load of tips on design in general from Dustin Stout.
I really like Dustin's style - he created the 'Plus Your Business!' logo - and likes to keep it clean and simple. Sounds good.
Check out the video to get to know him better too...
A few more thoughts...
Whichever approach you choose, know that the small things can make a huge difference - if people relate to your Profile or your Page they are much more likely to want to connect.