I pin on my dining room table and I put my rotary cutting mat underneath to protect my table. If your table is not big enough you can buy two folding rectangle tables and put them side by side - that might set you back about $150-$200.
You can also purchase knee pads to make kneeling A LOT more comfortable - or get that foam thing that I've seen in gardening catalogs that you can kneel on - or just get a piece of foam from JoAnn's.
I use really large safety pins - but I've seen a method advertised in some quilting catalogs that looks like it might be cool - it uses one of those "guns" and those plastic strips to baste your quilt - it reminds me of the "gun" i used when I worked in a retail clothing store as a kid - to put those plastic strips through the clothing to attach the price tag - I think www.keepsakequilting.com sells them and I was thinking about getting one - it seems a lot easier than pinning -but you would have to CUT each one off - which might be a pain.