I tried this on my eMac running Leopard, and on a 1.33 GHz iBook running Tiger. I have no idea if it'll be any good on older computers, but maybe it is worth a shot, since it seems to work for most videos even if quality will be very limited (3gp only, 176x144 for normal and 320x180 for HQ). Install Omniweb. Last update was back in 2012, but it should be secure enough for what we are going to do. Go on youtube.com and press command+option+, Omniweb has a very cool feature, you can define site specific preferences, and this pane will allow you to use a particular user agent for youtube only. Access the rightmost tab ("Other") then choose "Custom..." in "Identify to web servers and scripts as". Insert the user agent for the Nokia N90 phone: NokiaN90-1/3.0545.5.1 Series60/2.8 Profile/MIDP-2.0 Configuration/CLDC-1.1 By the way, this is the same trick used by Classilla to access mobile websites, I got the idea from there. If you reload youtube, you should be able to see a very lightweight version of it. Search for a video. If you select "Watch video" QuickTime should be launched automatically. If you have CorePlayer you can use the small application you'll find at the end of this post. Place it in the dock, copy the link to the clipboard than select YTCorePlayer to start playback (NB: if it doesn't work try enabling access for assistive devices in the Universal Access pane of system preferenes). This is the applescript code in it: tell application "CorePlayer" to activate tell application "System Events" keystroke "u" using command down keystroke "v" using command down keystroke return end tell You can save this as a script if you prefer to use Spark or something like that to launch it using a keyboard shortcut. So, why not using TFF or even better TenFourFoxBox? TenFourFoxBox at the moment doesn't allow to choose a custom user agent. Firefox/TFF has several extensions that would allow that (and one of them, UAControl, works on a per site basis, similarly to what Omniweb does), but the problem is mobile youtube just doesn't play well with TFF. You can only access the lower resolution files, and you won't get any audio from them in CorePlayer (strangely this doesn't happen when you get the links from Omniweb or Safari). Let me know if this works for you, especially if you have really old machines.