In Dynamics GP 2010 all Business Essentials(BE) users receive Field Level Security(along with Account Level Security and Electronic Banking Suite) at no additional cost.
This makes the recent post by Frank Hamelly on Field Level Security worth highlighting - http://gp2themax.blogspot.com/2010/05/gptip42day-fiield-level-security.html – He has a nice example “let's say you want to hide the Current Cost field in the Item Card from everyone but your cost accounting department. Here's how you do it with FLS:”
Using Field Level Security you can hide any field on a window from specific users. Without Field Level Security if you want to hide the Post or Approve Button on the Batch Entry window from specific users, you would have to use a customization or VBA Code. Field Level Security offers this out of the box. Field Level Security also allows you to assign passwords to make a field or window available to the users.
Some more resources -
Post by Janakiram at http://janakirammp.blogspot.com/2009/07/optimize-security-using-field-level.html
FAQ about Advanced Security and about Field Level Security in Microsoft Dynamics GP and in Microsoft Great Plains - https://mbs.microsoft.com/knowledgebase/KBDisplay.aspx?WTNTZSMNWUKNTMMYKKQRRUZVRPSSXNSNWTQZRSXSPOKVWULOKVZQXRMWLXVVUMZK