Semiconductors are the best examples of this, they have very significant temperature coefficients.
In general, any conductor has a temperature dependence regarding conductivity. Generally, heat decreases conductivity for metals. Semiconductors can go both ways; thermistors with both PTC (positive temperature coefficients) and NTC are readily available.
Regarding light: Metals generally aren't affected by light, but semiconductors are. When light strikes a semiconductor, electron-hole pairs are excited to the conduction band, increasing the conductivity. LDRs and photodiodes are examples of this. (Technically, all LEDs are photodiodes of a sort, just like all speakers can work as weak microphones)