I have done 3 oil changes now on my uneven crazy-paved front 'garden' using race ramps (foam ramps). I tried stands before with my previous car and never really felt safe with them. I got one of those cheap oil pans from machine mart.
couple of these for the front: http://www.raceramps.com/roll-ups.aspx
and these for the back to sort of level it out: http://www.raceramps.com/trak-jax.aspx
edit: oops, that does qualify as a ramp theres no way I could fit under there without a ramp.