I would say the same about really milky coffee!
Kale, turnip greens, collard greens and other dark green vegetables, dried figs, sesame seeds and nuts (esp. almonds) are all excellent sources of absorbable calcium. You could also try soya and tofu.
Sardines are high in calcium because you eat the softened bones. The added bonus is that they also contain omega-3 fatty acids, which are beneficial to the circulation and the heart, and vitamin D, which is important for the absorption of calcium.
http://www.datrondynamics.com/images/sardines. gif