In individuals insanity is rare, but in groups, parties, nations and epochs it is the rule.

Friedrich Nietzsche

Accounting

AceMoney Lite Version (Single User) is just the thing for your small business or personal finances.
AceMoney works well under Linux with Wine
http://www.mechcad.net/products/acemoney/index_lite.html
http://www.mechcad.net/downloads/AceMoneyLiteSetup.exe

Personal and small-business financial-accounting software, freely licensed under the GNU GPL - Windows, Mac OS X and Linux.
www.gnucash.org

PLCash is a platform-independent personal finance program. Runs on Windows, Mac OS X and Linux.
http://www.arachnoid.com/PLCash/index.html
Windows
http://www.arachnoid.com/PLCash/PLCash.exe
Jar file for Mac OS X and Linux
http://www.arachnoid.com/PLCash/PLCash.jar
NB: PLCash needs at least v1.4 of Sun's Java runtime to run.
http://www.java.com/en/download/installed.jsp