  Using recent measurements of angular size of high-z milliarcsecond compact
radio sources compiled by Gurvits, Kellermann and Frey (1999) and X-ray gas
mass fraction of galaxy clusters published by Allen et al. (2002,2003), we
explore their bounds on the equation of state, omega_x = p_x/rho_x, of the dark
energy, whose existence has been congruously suggested by various cosmological
observations. We relaxe the usual constraint omega_x >= -1, and find that
combining the two databases yields a nontrivial lower bound on omega_x. Under
the assumption of a flat universe, we obtain a bound -2.22 < omega_x < -0.62 at
95.4% confidence level. The 95.4% confidence bound goes to -1 =< omega_x <
-0.60 when the constraint omega_x >= -1 is imposed.
