Convenient way to follow a transaction chain?

[LordNacho]

On blockchain.info it's possible to look at a random transaction and see where it came from and where it was spent. You can click back and forth until you find an unspent transaction at the end of the chain (or coinbase at the beginning). Unfortunately, the JSON call doesn't seem to return the same source/sink info as the web page (or am I wrong?)

I'm looking for a simple interface for doing this on BitcoinJ. At the moment, all I can think of is to scan future blocks for sequential transactions as inputs, but that doesn't seem very efficient, in time or storage space required. Perhaps there is a way using just the block headers this could be done?

[LordNacho]

Okay, so I've found a couple of solutions.

1) Parse the web pages of the explorer services.
2) Manipulate the Bloom filters in the newer versions of the protocol.