Just a quick summary of more or less known features, see also http://www.igniterealtime.org/community/blogs/ignite/2007/03/19/spark-goodies
As they are mostly unknown they are broken for some versions, sad thing but must be said here.
Main Window
Ctrl+E Recent Conversations
Ctrl+F Find Contacs which are on your roster, if there are too much (2.0.2)
Ctrl+N Find Contacs which are on your roster, if there are too much (only 1.1.x)
Ctrl+T Favorite Contacts
CtrlF5 Tasks (only for 2.0.0, 2.5.6 while 2.5.6 has an icon for this)
CtrlF6 Notepad (only for 2.0.0, 2.5.6 while 2.5.6 has an icon for this)
F8 Jabber Browser
F12 Traffic Window (not for 2.5.4+ - there one need to open the debug window during login)
Drag-and-Drop files on a contact to send them
Conversation Window
AltLeft and AltRight (one could expect Ctrl+Tab to do this) changes the buddy tab you are talking to.
Only within P2P Chats
Ctrl+V sends the content of the clipboard (works with images, I didn’t test with other content).
Drag-and-Drop files in the chat window to send them
Nested Groups
If I wanted to have the following nesting:
Buddies
- Work
- Personal
You would create a shared groups like this:
Buddies::Work
Buddies::Personal
One should be able to configure this and use ‘/’ instead of ‘::’, change it here: TODO
Funny Things
… which are not hidden, just documented here. Get them within the “Traffic Window”, “Ad-hoc message”
Query Client Version
Note: Spark 2.0.1+ offers a popup menu for this within the roster
<iq id="i1" to="foobar@example.com/spark" type="get">
<query xmlns="jabber:iq:version"></query>
</iq>
Query Client Time
<iq id="i1" to="foobar@example.com/spark" type="get">
<query xmlns="jabber:iq:time"></query>
</iq>
Invisibility / Privacy lists
see Privacy Lists
or http://www.igniterealtime.org/community/thread/21886 (quite old)