Excerpt from my current iPhone apps list

Categorized, though mostly focused on remote controlling and media access, along with some notes:

[Remote] Media Control/Playing:

• MPoD - controls mpd, my Home Stereo system.
  
• dreaMote - controls your DreamBox DVB Receiver.
  
• XBMControl - controls XBMC, the great Media-Center.
  
• (non-free) PlugPlayer - UPNP Media Control (Experimental).
• (non-free) iMediaSuite - UPNP Media Control (Experimental).
• iLirc from daspider - LIRC Integration, unfortunately not (yet?) in the App Store, so currently only usable on phones with removed App restrictions. (Thus currently non usable for me)
  

Generic remote control applications:

• Touchpad (non-free) - Use your iphone as external wifi touchpad.
• TouchTerm - SSH Client with some nice features.
  

WebDAV-related, and not bound to specific providers:

• Disks - Supports SSL Connections. Still testing.
  
• DAV-E free - Still testing.
  

Communication:

• XSPhone - SIP VoIP Client, configurable for other providers.
  

If you know any noteworthy additions to above list, or have any other hints or notes, like free functional equivalents to the non-free applications, feel free to drop me a comment.
I will update this post as time progresses. Thanks for reading.