Taxi

There are several reputable taxi companies, charging strictly metered fares.  When arriving at the airport you'll see a queue of Martonas yellow cabs.  These are OK, the cost of a trip to city centre should not run you more than 20 Litas during the day and 30 Litas at night.  DO NOT PAY MORE.  Look on the dash near the driver for an English toll-free quality number if you have any problems.

It's much cheaper to call a cab.  Two good companies:  MERSERA +37052788888 and MARTONAS +37052440044.  Others are good too, but I find these speak English reasonably well, cars are clean and drivers aren't too smelly.