Characters such as Mickey, Minnie, Donald, Goofy, Pluto, Chip and Dale, Cruella, Alice and the Mad Hatter come out to Main Street frequently in Disneyland. In the Sunshine Plaza at DCA we've seen Mickey, Minnie, Donald, Goofy, Pluto, Chip and Dale, Lilo, and Stitch. The Fab 5 (although Donald only infrequently in my experience) can be found in ToonTown. Pooh and friends hang out in Critter Country. Tinkerbell and her fairy friends are in Pixie Hollow near Tomorrowland. The princesses are mostly at the princess fantasy fair. Then, of course, there are always character meals, parades, and shows (Disneyland band performances, Drawn to the Magic in DCA, etc.). As for "roaming", I agree it doesn't seem to happen much compared to all these planned appearances, but sometimes you can get lucky. We have come across Peter Pan more than once roaming through Fantasyland and even hiding in bushes and startling passersby. Alice and the Mad Hatter roam often as well. Mary Poppins and Bert come out and perform near Carnation Plaza or Coke Corner. Woody and Jesse wander along the trail in Frontierland and also hang out near Paradise Bay and Toy Story Mania in DCA. We occasionally run into PUSH, the talking trash can, along the Grizzly River trail or near the Little Mermaid ride-to-be. I think our most memorable chance encounter though was with Belle and the Beast near the castle one midday about a year or two ago, but we didn't stop because as soon as other people spotted them, they were mobbed.