HikeArizona.COM

So, Trail 25 exists on HAZ ( http://hikearizona.com/images/maps/phx/lookout.gif ) and at the Phoenix gov site ( http://phoenix.gov/webcms/groups/intern ... hlarge.pdf ... big .pdf!) but when I look at the MapDex satellite view, I don't see a trail, even when I zoom in close. It looks like the "trail" would either be through someone's living room -- pretty nice loving room at that! -- or down the streets. So, has anyone ever hiked this legendary trail? Does it exist, or is it El Dorado?

According to the PHX pdf you linked to, 25 is an "undesignated trail".

Which I think means "Good luck! You're on your own."

Must have missed that part.

I've done part of that one.. it basically just winds around between houses and branches off in several spots. Nothing to write home about, but it's nice to have a connector between the parks.

So here's the map: http://hikearizona.com/map.php?MY=2102&M=5.

Trails marked as "Trail 25" and "Trail 25A" are drawn as on printed Green Trails map and they totally exist. You can easily see them if you zoom in the satellite view.
Trail 25A follows the sidewalk of Pointe Golf Club Dr from the Thunderbird crossing, turns west on Hearn Rd and after the first house turns north onto a back alley between residential backyards then entering Lookout Mtn Preserve.
Trail 25 goes east along the south side of Thunderbird Rd, crosses it supposedly by the tunnel and ends at Mirador apartments road.

Trail marked as "Trail 25 phx.gov" is a trail drawn on official Phoenix Parks map that you linked to. It can also be traced on sat view but it follows what I believe are golf cart driveways, so it may be not a pleasant hike with those heavy golf balls flying all around you.
Trail 25A marked red on http://hikearizona.com/images/maps/phx/lookout.gif doesn't exist and Trail 25 marked blue on that map is completely off between Thunderbird Rd and Lookout Mtn.