Wow, I don't use Stitcher, but just downloaded to try it. Downloaded as 4.6mb, and I could move it to SD (not rooted) and it's now 1.7mb. I have 86 apps:
tcat007's Apps on the VM670 - Page 1 and have 40.4mb free. I listened to a Stitcher station for 10 minutes, my cache cleaner app has 180k shown for stitcher. It's prefs has "use SD" checked as default, I assume it's caching to SD. (yes, I just checked and a "stitcher" folder was created on SD and cache and files are there)
I use SD Watch to monitor which apps can move to SD. I use "App Cache Cleaner" to clean cache daily. I try to find small apps that do the same thing as "big" apps, and/or ones that can be moved to SD. I have apps I don't use much uninstalled either at Amazon, or backed up to SD, until I really need them. All the apps in my list above are installed, of which at least half could probably be backed up and uninstalled, but until I have ROM issues, I'll leave them alone.
I love my Optimus, just wish it had Triumph's screen!