microRNA database - in both animals and plant (Dec/16/2009 )

I would like to do some search on microRNAs and their targets.

Among many sties list on google search.
Is there microRNA data base that people generally think is useful (or consider better)?

By the way, just been lazy, is there any web site(s) that have summarized microRNA function, target and ot regulation?

Thanks

Here you are:

miRBase: the microRNA database http://www.mirbase.org/

MicroCosm Targets (formerly miRBase Targets) is a web resource developed by the Enright Lab at the EMBL-EBI containing computationally predicted targets for microRNAs across many species.