smartLookup for Plaxo is a free application for Java J2ME based mobile devices that allows you to synchronize contacts under each subfolder along with all the custom fields from Plaxo Web to your mobile phone.

Here are some of the key features of Smartlookup for Plaxo:

-smartLookup uses the same uses the same set of fields as Plaxo address cards such as home, mobile, fax, business, pager number, Skype Id, card message, webpage, address, birthday, etc
-support for contact folders: You choose which Plaxo folders to keep in sync
-call any phone number listed in your contact directly from smartLookup program
-select ‘Display As’ format: ‘Last, First’ or ‘First Last’.
-search contacts within any subfolder
-encrypts data transmission by randomly generating a PIN

Download from Smartookup Plaxo for Java J2ME mobiles from here[GetJar].