Please go to this linkhttp://redbeltboxer.deviantart.com/art/Welcome-To-Lava-Island-WIP-212303398 to see image as it wont display here. I am interested to know if someone can work out a way to make the text in LAVA ISLAND look like is cracking.
This image reference is here http://abduzeedo.com/create-lava-island-scenario-illustrator

Try using the pencil tool, smoothing at 1, and use the Ellipse shape.

-Rob A>

There are some wonderful filters. You might find one of them will give the effect that you want. Depending on which Inkscape version you have, you might find even more filters in the ivan_louette collection at the Open Clipart Library (http://www.openclipart.org/).

Btw, do you mean the text is cracking in half, or into pieces?

EDIT
There's actually a filter called Cracked Lava! Filters > Materials > Cracked Lava
Might work?