Lots of options, though most are for specialized wizards (which is a very good tradeoff, btw - you don't lose too much versatility by giving up Enchantment and Evocation and specializing in Conjuration or Transmutation). Can't think of any for generalists off the top of my head, but I'm positive there's more.
For specialists, there's Immediate Magic (Most suck, but the conjuration one is chiseled masterfully from a block of pure, solid Win), from PHB II. Each school also gets three ACFs in Unearthed Arcana, one of which trades away the familiar.