I've never come across it before but we see it in all the shops out here and apparently is used a lot in Thai cooking.
Fresh Galangal (aka galingale, blue ginger, Siamese ginger, Thai ginger) has a flavor evoking ginger and pepper with hints of citrus and pine. It is used in Thai, Malaysian, southern Chinese and Indonesian food. It is a relative of ginger and turmeric.
Found a recipe for coconut soup we might try that uses it.