I have been inspired lately to grow raspberries or blackberries. The back-yard is prime real estate (veggies and dog play area) and I would hate to add a thicket of brambles for her to stumble into. I would love to just put down a berrybush in the front yard, but I really don't want to build a support/ trellis. I think it would be a huge eye-sore and although my front yard is far from pristine, I don't want to give my neighbors any reason to cause trouble. Can I just have then sprawl out across the ground? Would it really make harvest impossible, or would it just become a huge bush? I already plan on putting down a few blueberries, but I would really like some variety.

Raspberries do fine without support in my experience. They will spread via the roots, so you will need to occasionally dig up some plants to keep them contained.

I've seen blackberries grown without supports. The key with these seems to be cutting back the primocanes - the vigorous stems that grow in the spring/summer and will have next year's fruit - to about 18". They will bush out and support more fruit on a shorter stem. To stop a blackberry thicket taking over you need to stop stem tips touching the ground where they will root. Basically, blackberries can be done but need regular maintenance through the growing season.

You can certainly grow blackberries without a support. A couple of years ago I planted the blackberry bushes shown below and have besides pruning off dead branches from time to time, all I've done is harvest the berries. To be fair, the blackberries don't look all that nice in the winter, but then most things outdoors in Indiana during the winter look pretty grimy.