Is it OK for air conditioning condensation to drip right next to the house?
I've read a few sources on this and there seems to be some argument on what the best practice is.  This thread at InspectorsJournal is similar and the conversation quickly shows that even most of these inspectors have different opinions when it comes to A/C drainage.  A lot of the difference though, is geographic location of the home, and whether the ground around the drain slopes away from the house or is flat.

The example in the image below if from the EPA in their guide for moisture control around the foundation.  Not all the guide will be useful and its not exactly your situation, but you can check it out here.



If the water is not running away from your foundation and sitting stagnant against the it, I would drain the water.  TodaysHomeOwner.com has a good article on possible solutions.  Though the topic is for a drain directly from an exterior A/C unit, the principles should be the same.

If you can't extend your 3/4" PVC easily, exterior hose clamps and hoses should be available at your local home improvement stores.  Most of clamps are stainless steel and should work fine.  Plumping departments should have hose by the foot that would work as well.