I started playing with Tiled Clones in Inkscape 0.48.
Just walking thru the menu and options and creating samples.
What can be cloned?
Text? Yes. Must be converted to path first, otherwise the text won't rotate and get unexpected results.
Effects? That heart I created and then added a filter to can be cloned as is. That was unexpectedly easy. lol
I thought this seamless tile was pretty:
Seamless, transparent background, free to snag if you want it.
Here's what it looks like tiled.
Letter "a" with gradient, Convert to Path,
Glide Reflection 180
If you want to clone more than one object at a time, they have to grouped first.
There's a Clone section in the File, Inkscape Preferences area.