"Basic flow charting can be done in MS Word"

It never ceases to amaze me that so many people waste so much time faffing around with MS-Word's abysmal drawing facilities. Just say, "No!"
MS-Word is a wordprocessor, and it is good at wordprocessing; it is not a graphics or drawing package, and it is rubbish at graphics and drawing!
MS-Word has exellecnt import facilities, so don't waste any time at all even thinking about doing drawings in Word - get a proper drawing/graphics package - free or otherwise!

Personally (and professionally) I use and recommend Visio - it's certainly not free, but it's well worth the price just in terms of frustration saved over using Word-Art!!

Without going to a full CASE tool (even more expensive still, and less flexible) Visio is the only general-purpose tool that I've come across that knows about connections - so when you move a box on your flowchart, it stays connected to its predecessors, successors, etc. Try that with Designer, Word-Art, etc!

I believe that there are add-ons available which will source code (MSVC, VB?) in and generate Visio diagrams from it; dunno about flowcharts from plain ANSI 'C', though...