How to make bitcoins from other cryptocurrencies? I want to know how can I convert other cryptocurrencies like BlackCoin or LiteCoin to Bitcoin. There are many cryptocurrencies out there and the main difference between most of them and Bitcoin is popularity. At the moment, Bitcoin is way more commonly accepted as a payment option than the other cryptocurrencies, so they aren't really useful or flexible at all... So please tell me and explain how can I do this!
The only way to convert them is by trading one for the other, or by going through a third currency. 

Meaning:


Find a person or exchange platform that trades exactly the currency pair you want e.g. LTC/BTC or BLK/BTC.
Trade LTC -> USD -> BTC


Some exchanges trade a number of different altcoins, so they would lend themselves to do what you want. I have no experience trading anything but Bitcoin, but I've seen that for example HitBTC trades LTC/BTC, and BTER trades BLK/BTC.

I have used neither exchange and therefore cannot recommend them, just giving them as examples.