Does anyone else ever think of songs in their head and then start melding two ditties into one? For example, I can't help but 'merge' the following songs:

Maroon 5 - Move Like Jagger with Modjo - Lady Hear Me Tonight

Abba - Eagle with Abba - The Name Of The Game

Blondie - Danceway with David Bowie - Modern Love

'Heaven Must Have Sent You' by the Elgins with 'True Blue' by Madonna
'You're No Good' by the Swinging Blue Jeans with 'We're Through' by the Hollies
'Groovy Kind Of Love' by the Mindbenders with 'I Can Hear Music' by the Beach Boys.

See where you're coming from on the first 2.

This is a very weird pairing but...

Break The Ice and We Belong Together

Do you mean the 'Break The Ice' by John Farnham, Ryan?

The term is 'mashup' - there are loads of great ones on youtube, some very funny

Yes a recent great one i heard was Whitney Houston and Robyn dancing on my own mixed with how will i know epic

One not so good Land Del Rey Video Games mixed with This Charming Man The Smiths

check them out on Youtube

Funny enough, someone on youtube made a mash-up of
Leona Lewis - Collide
Rihanna - We Found Love
David Guetta / Kelly Rowland - When Love Takes Over

Now everytime I hear one of these songs, I have the mash-up playing over in my head. I wish they had all came together and made this song
http://www.youtube.com/watch?v=U78MoLH8SFs