Icon: src/qt/res/icons/clock*.png
Designer: Wladimir van der Laan
License: Creative Commons Attribution

Icon: src/qt/res/icons/send.png
Icon Pack: Vista Style Arrow
Designer: Icons Land
License: Freeware Non-commercial
Site: http://findicons.com/icon/231371/right3green

Icon: src/qt/res/icons/address-book.png
Icon Pack: Farm-Fresh Web
Designer: FatCow Web Hosting
License: Creative Commons Attribution (by)
Site: http://findicons.com/icon/163938/book_open

Icon: src/qt/res/icons/connect*.png, src/qt/res/icons/synced.png
Icon Pack: Human-O2
Designer: schollidesign
License: GNU/GPL
Site: http://findicons.com/icon/93743/blocks_gnome_netstatus_0

Icon: src/qt/res/icons/transaction*.png
Designer: md2k7
Site: https://forum.bitcoin.org/index.php?topic=15276.0
License: You are free to do with these icons as you wish, including selling,
 copying, modifying etc.

Icon: src/qt/res/icons/configure.png, src/qt/res/icons/quit.png,
      src/qt/res/icons/editcopy.png, src/qt/res/icons/editpaste.png,
      src/qt/res/icons/add.png, src/qt/res/icons/edit.png,
      src/qt/res/icons/editdelete.png, src/qt/res/icons/remove.png (edited)
Designer: http://www.everaldo.com
Icon Pack: Crystal SVG
License: LGPL

Icon: src/qt/res/icons/receive.png, src/qt/res/icons/history.png,
      src/qt/res/icons/export.png
Designer: Oxygen team
Icon Pack: Oxygen
License: Creative Common Attribution-ShareAlike 3.0 License or LGPL
Site: http://www.oxygen-icons.org/

Icon: src/qt/res/icons/bitcoin.png, src/qt/res/icons/toolbar.png
Designer: Bitboy (optimized for 16x16 by Wladimir van der Laan)
License: Public Domain
Site: http://forum.bitcoin.org/?topic=1756.0

Icon: src/qt/res/icons/overview.png
Icon Pack: Primo
Designer: Jack Cai
License: Creative Commons Attribution No Derivatives (by-nd)
Site: http://findicons.com/icon/175944/home?id=176221#

Icon:  scripts/img/reload.xcf (modified),src/qt/res/movies/update_spinner.mng
Icon Pack: Kids
Designer: Everaldo (Everaldo Coelho)
License: GNU/GPL 
Site: http://findicons.com/icon/17102/reload?id=17102