I just checked and the Xero filters are pretty much onestep solutions for this. In Photoshop you could use Render/Clouds colored as Carolly suggests to make a background image to import into Poser. I often fake spot lights by putting a round gradient on a Linear Burn layer. I fake depth of field by putting a round gradient mask on a median filtered duplicate layer, then I can fine tune it by painting on the mask with a soft brush, playing with contrast/brightnes on the mask, and adjusting opacity for the layer. Spot coloring I do on a layer set to "color" mode so it is easily reversable. But those filters above will pretty much get what you want from one dialog box.