There is a new feature on befunky.com, it is called "Collage" and it gives very decent results. It is especially useful if you maintain a blog and need collage pictures for your articles.
As for me, I usually use just 3 squares designs or other extended designs.
I will use 3 Pictures of Bhagavan Shree Narayana as an example below.
The only bad feature in this collage creator, that it gobbles a part of the image. So, when you are preparing the Images for your collage, make the image a little bigger, than you expect it to look in the collage, that is leave the space, that will be gobbled by this editor!
So, I have 3 Images of Bhagavan Shree Narayana:
Actually, I have cropped the parts I need beforehand (you can use "Edit - Crop" in IrfanView or just any screenshot maker in order just to save the part of the image you need - I use Lightshot programme).
Now go to http://www.befunky.com/, choose Collage (upper, right corner in red, I am sorry for Russian language on the picture, but it is impossible to change!)
Now, choose any GRID you need, I am using very simple 3 Squares Grid.
Now, go back to very first tab, where added photos are stored. All you need now is to drag the Images into the squares. Don't forget, that every square has "EDIT" button (the notepad with pen on the each square).
Now the feature I liked the most - "ROUNDED ANGLES". It is in the Third Tab. As you see on the picture above it is called "Закругление углов" in Russian (yes, hahaha, tricky language)!
Ready!
Now it is time to save the Image, but if the size is very large (it was 4.4 MB for PNG), just change the size on the left (not 2400 x 800), but, for example 1200 x 400.
After the change the size is just 1.1 MB for PNG, which is OK for blog (I don't use JPG, because Google usually diminishes the quality of the image, when you publish in blog).