The Amazing Granny Square is the building block for many a good quilt, sweater, vest, shawl, scarf, potholder, pillow. I've used a variation on the great granny in this vest. The yarn is Bernat's Mosaic and takes about 3 skeins.
http://www.etsy.com/listing/88954970/sale-maid-marion-sweater-vest-sleeveless?ref=sr_gallery_9&ga_search_query=needlemaven&ga_view_type=gallery&ga_ship_to=ZZ&ga_min=0&ga_max=0&ga_page=2&ga_search_type=handmade
Happy hooking to you! Kim