Does LVM affect performance

[WipeOut]

Hi,

Pretty simple questions but probably not such a simple answer..

Does using LVM affect disk and system performnace?

There must be some overhead involved (memory, cpu or disk IO) in using
LVM but is that overhead measurable or is it insignificant if disk 
throughput is of significance??

Would be interesting to hear your thoughts or from anyone who has tested
it..

Thanks..