What kind of bike (road, mtn, hybrid, etc)? You'd be surprised how underinflated "hard" tires can be. I find with my road tires, they feel rock-hard to the touch at 60-ish psi, but they need to be inflated to 100-110, and anywhere from 60 up doesn't feel any different to the touch. And yeah, I made that mistake on one ride, hit a crack and flatted BOTH tubes (underinflation + impact ==> "snake bite" puncture). No cell phone, only one spare tube, long walk home.

What you really need is a decent quality floor pump with a built-in gauge.