I know this has been discussed before - and I've read some of the old threads on it.

But how feasible is this to implement?

Say if you have coins that haven't moved for 50?/100? years - could you add them back into circulation? Via the miners - also potentially more incentive to keep mining? a Little bit of extra on top of the Tx fees?

I like the idea of having the Bitcoin client move coins every X years automatically to avoid you having to do anything and falling foul of the 50/100 year limit. And if you make the limit say 100 years no one could be saving for that long, so thereby almost undoubtedly meaning that the coins are lost.
Would this be a difficult change to add?

What are the disadvantages? vs what are the advantages?

I know you could theoretically have the bitcoin network with just 1 bitcoin but surely ensuring that lost coins are recycled if they are indeed lost, not too often (hence 100 years or so), is the best option?

Opinions?