What current technology? The energies involved in getting something to 99% of C are insanely high (the kinetic energy of each kilogram at that speed is about the same as the output of a 132Mt bomb).

Then there are the problems of traveling at that speed - which are significant.

"Realistic" designs for interstellar probes generally rely on not carrying the fuel with the probe and having ultralight masses (e.g. Bob Forwards "Starwisp" http://en.wikipedia.org/wiki/Starwisp) - this still requires impressive engineering (a 560km diameter transmitter producing 56GW) for a total probe mass of 1kg and payload of 80g. And that would "only" manage 20% of C.

http://en.wikipedia.org/wiki/Starwisp

Do I believe something like Starwisp will be built - absolutely. In my lifetime? No chance.

I'd be happy if we get people to Mars in my lifetime - something I don't expect to see.