What is this weed? Need help please

 Hello,
I am tring to find out what kind of weed this is and how to control it.
http://slipkid.smugmug.com/photos/68243410-M.jpg
Thanks

 This looks like speedwell.  Corn speedwell is an upright, clumping
winter annual that produces small purple flowers in the spring. Corn
speedwell does not typically persist very long after flowering.
Attempts to control corn speedwell in the spring are usally
unsuccessful because the plant is at the end of its lifecycle. This
type of weed is best controlled with a post emergent herbicide during
its peak in may or november.

 Thanks for the reply.

 I don't know exactly what it is, but I have some of it and Weed B Gone
whacked it.  I would think any broadleaf weedkiller would work.  I'd go
with liquid and a small tank sprayer to deliver it right on target for
max effectiveness and minimum usage.

 Ciscoe Morris our local TV gardening guru suggests spraying any weed or
unwanted grasses between concrete cracks with straight vinegar on a hot
sunny day.
I have tried it and it really works and is fairly non-toxic....you don't
want to get the vinegar on ornamental or other desired plantings though/
You can read Ciscoe Morris's website by typing his name into search.