The native simple/basic search in WSS3 is very limited and doesn't offer greater flexibility. One needs to build custom advanced level search to achieve more power to the search. At WebKMS, we have extended the native WSS3 simple search without really complicating the simplicity of the functionality.
The extended WSS3 simple search functionality offers much better control and yet maintains the easy to use approach. Apart from providing the ability to perform partial keyword search, a boolean OR search, the functionality also extends configuring other search settings like whether to trim the duplicates, sort by specific fields, ignore noise words, disable stemming, how to show the search results, etc.,.