Useful tips
Press Ctrl+F (while in the contacts or chat window) and start filling the name. It will automatically filter out from all of your contacts. This is a fast way to find a contact in a huge roster.
Press Ctrl+T (only works in a roster window) - it will show frequent contacts, the people you chat most with.
Press Ctrl+E (only works in a roster window) - it will show a list of users you had conversations with recently. A quick way to find whom you were talking with recently, if you can’t remember the name.
Pressing Ctrl+Space after you enter a few characters of someone’s name in the group chat will complete the name automatically.
If a contact you want to talk to is Away (or even Offline) and you want to know right away when he is available. Right-click such contact and select Alert when user is available. Spark will open a chat windows with that contact once he gets Online. Note: Spark will remember this task only until it is turned off.