Swift Keys isn't too costly and does what you need:
SwiftKeys is an automation and
productivity utility that allows you
to automate mouse clicks, keystrokes,
text and other repetitive tasks on
your desktop screen. By creating
macros or "snippets" for your mouse
and keyboard. The application allows
you to record and automate a series of
mouse clicks and keyboard keystrokes
on any Windows PC. To start the
recording a mouse snippet, press the
"create mouse snippet" icon, press
"Record" and start the mouse movements
you want the macro or "snippet" to
record. To replay the recorded
sequence, simply enter your keyword in
any application, and SwiftKeys will
take over and play your snippet. To
start a text snippet, press the
"create text snippet" icon, enter in
the keyword and text you want
associated with that keyword, then
save, SwiftKeys will now insert the
text any time you enter the keyword in
any application. Works in Microsoft
Word, Excel, Outlook, Notepad,
Photoshop, and any other Windows
application.
For a free solution you could use AutoHotkey although you'd need to make all of the abbreviations yourself, example:
::lol::laughing out loud
::ppl::people
::su::Super User