How can I free up more space on my Android (2.2 Froyo) phone? I have already moved all the applications that allow it to the SD card. So what I am really looking for here are some tips like clearing internet cache or something like that. (I have an HTC Desire.)

Edit: In my case the top space hogs are:


Google Reader - 19.1 MB
Swype - 10.7 MB
Maps - 9.2 MB
Contacts Storage 8.9 MB
SliceIt - 8.2 MB
doubleTwist - 6.4 MB
Facebook for HTC Sense - 5.9 MB
Handcent SMS - 5.0 MB
Adobe Reader - 4.7 MB
Gmail - 4.2 MB


and there are many more after that (TweetDeck, Bloomberg, Angry Birds, Shazam, ...).

Now I know that I have a lot of apps but that's what I want from my smart phone and I don't really want to have to uninstall anything. I've also got a 16GB SD card which is over 50% empty so if only more of the apps would allow themselves to be moved to the SD.

EDIT 2: I found this question - How can I deal with "Low on space" messages on my HTC Incredible?  which deals with the same issue and the accepted answer there is very good.
I have an HTC Desire, too, and I really had the same problem for a long while. 
Until I found this post:
http://www.getele.com/how-to/how-to-install-apps-to-your-sd-card-on-android-froyo.html

You do NOT have to root the phone, or something like that. It tells you to download the Android SDK to your computer, then connect it via USB and enter only one small one-line command. After that, ALL apps (except system apps) will be moveable to SD card, and also have SD card as default install location. 

Since then, I really get the most out of my phone, and have dozens more apps. At the moment about 130 apps. Some of them shrink from 23mb to 120kb, others are not so drastic, but it REALLY helps.

Hope I could help,
Heval