if you like house music, you can go to club "connect" there will be "RyRalio House:
Sobieski uogos CD Presentation Party. http://www.ore.lt/img_up/jay%20j%20flaika_2.jpg
but i don't suggest you;]

i think the best choice on 18th is http://www.ore.lt/img_up/Stereo45_3_WEB.jpg
electro;], now it's popular in vilnius, so i think there will be the biggest party in vilnius on 18th..

also in the same building, will be drum'n'bass,
http://www.ore.lt/img_up/arka-2005-4-a-600.jpg

can check both

after everything if you tired, the best place to eat and rest some "cozy", it's like a dj bar, on 18th there will be some electronic, EXITLABEL djs.

For 19th, in the same cozy will be the Boogaloo party
http://www.ore.lt/img_up/BooExclusive2A.jpg
this time cozy will be not just for eating or resting;]

check www.ore.lt kalendorius
there you will find all vilnius partys