You got me thinking... How about if we developed a "landing" system that consists of the following:

• A container for a block of a gas that remains solid at space temperatures and doesn't need cooling (to avoid having to waste weight on a complex system to keep it cool -- just a shade from the sun and nothing more).
• The landing probe itself, with some propellant but not too much.
• A shield for the landing probe.
• A strong parachute/sail.

So the landing mechanism would be as follows:

• Upon getting close to the target, the landing probe separates from the "block of ice" (imagine it's CO2 for the purpouse of this explanation).
• Both continue on pretty much the same trajectory, but the dry ice is ahead by a certain distance (which should have to be properly calculated).
• The landing probe releases the parachute/sail and prepares it for...
• The impact/explosion of the dry ice on the surface. This releases a lot of energy and an expanding bubble of gas upwards...
• ...that helps the parachute/sail slow down the landing probe.
• There could be some remaining fuel onboard to make a "soft landing".

Of course I can imagine a million things going wrong here. The lander should have a strong shield to survive the energy from the impact/explosion. So should the parachute/sail. The block of ice has to be ahead a certain distance, and you have to balance the damage the explosion can do on the lander and the force it exerts on it to get the desired slowdown. The parachute/sail would need a mechanism to avoid extreme acceleration opposite to the direction of the probe, etc.

But with all the problems it has... I don't know, I feel like simulating this and at least seeing if it's remotely possible could be interesting. I'm sure it'd at least be fun for those who worked on it :P