Feature Request: Optimizer tuning

There is one thing I really miss when working with PostgreSQL.
In many cases I have to optimize complex queries (8-10 tables, views and 
tables, ...).
I can define if indexes are used or not but it would be fine to turn 
indexes on certain tables off temporarily.

At OSCON Gavin Sherry has mentioned that it should not be hard to add 
this to PostgreSQL. I guess we'd need an internal list which sets the 
costs of an index to infinite in order to make it unused.

This would make many things so much easier and so much faster.
I agree with Tom when saying that improving the optimizer would be 
better but this would be an immediate, easy to achieve help for many 
people out there.

Could anybody implement that? I am not enough into Postgres internals to 
implement it myself.
Regards,    Hans