If efficiency is an issue, then consider a Switch Mode regulator [SMR] followed by a low-dropout linear regulator. Set the SMR output voltage to 5V plus the worst case dropout voltage of the linear regulator. For instance, for the LP2050-50, the worst case dropout voltage, for an output current of 100mA, is 600mV. So, set the SMR output voltage to 5 + 0.6 = 5.6V
Using the graphs in the LP2905 datasheet (for instance Figure 12 and Figure 13, in the TI datasheet), you might be able to tighten that up even more [knowing the actual specifications for your application].
That way, you get the benefit of the SMR's efficient energy translation, along with the clean output of a linear regulator. Setting the SMR as close to 5V as possible, without compromising regulation, insures minimal power loss in the linear regulator.
As allanhurst mentioned, the LP2950 is a good choice, as long as it can handle whatever current demand exists in your application (I didn't see a mention of that--but I can't imagine a tilt sensor would have much of a demand).