From clothing: Wipe off paint residue with a paper towel, then sponge on a solution of laundry detergent and warm water. Once the paint has softened, remove as much as you can with a dull knife. Rinse and repeat until the stain is mostly gone. Machine-wash normally.
From carpet: Try to keep the paint stain damp for best stain removal. If dried, use a hard-bristled brush to remove as much paint as possible, then add a paint and varnish remover and gently scrape away the paint as it softens. Sponge the stain with a mixture of water and liquid dishwashing detergent. Blot, then apply a solution of one part white vinegar to 10 parts water. Sponge with water, and blot dry. Repeat the steps as necessary.