Blogging:

Wordpress.com  - Free blogging program
Blogger - Free blogging program

Wordprocessing, Spreadsheets and more:

OpenOffice.org - Word processing, spreadsheets, presentations, graphics, databases and more

Image & Editing Software:

Paint.net - Free image and photo editing software

Inkscape - Graphics and image editing 

Remote Computer Access:

LogmeIn - Access your computer from anywhere