This website has already mentioned how you can earn 100 Miles&More points by submitting hotel reviews via www.tripadvisor.in.
Technically, it seemed that you needed to review Indian hotels, but points are (currently) being awarded for all hotel reviews.
There’s now an alternative to the tripadvisor.in route – www.holidaycheck.com. Submit your reviews through holidaycheck and you will earn 100 Miles&More points per review (to a maximum of ten a month).
Obviously, if tripadvisor.in start limiting the Miles&More points they dish out to Indian hotel reviews, holidaycheck becomes the key – you just then need to decide whether you want to earn M&M points or BalticMiles for your reviews (but don’t forget to review all those Indian hotels you’ve stayed in through tripadvisor.in…).
A quick reminder that AirBaltic (on which you use BalticMiles) will fly to Malta from Riga beginning in May 2013.