  We report the discovery of two new variable stars in the metal-poor globular
cluster NGC 288, found by means of time-series CCD photometry. We classified
the new variables as SX Phoenicis due to their characteristic fundamental mode
periods (1.02 +- 0.01 and 0.69 +- 0.01 hours), and refine the period estimates
for other six known variables. SX Phe stars are known to follow a well-defined
Period-Luminosity (P-L) relation and, thus, can be used for determining
distances; they are more numerous than RR Lyraes in NGC~288. We obtain the P-L
relation for the fundamental mode M_V = (-2.59 +- 0.18) log P_0(d) + (-0.34 +-
0.24) and for the first-overtone mode M_V = (-2.59 +- 0.18) log P_1(d) + (0.50
+- 0.25). Multi-chromatic isochrone fits to our UBV color-magnitude diagrams,
based on the Dartmouth Stellar Evolution Database, provide <[Fe/H]> = -1.3 +-
0.1, E(B-V) = 0.02 +- 0.01 and absolute distance modulus (m-M)0 = 14.72 +- 0.01
for NGC 288.
