So Sparrow doesn't need to be in your dock:
on alfred_script(q)
tell application "System Events"
set isSparrowRunning to exists (processes where name is "Sparrow")
end tell
if not isSparrowRunning then
tell application "Sparrow" to launch
delay 0.5
end if
tell application "Sparrow" to activate --- activates sparrow
tell application "System Events"
tell process "Sparrow" --- implying Sparrow is already activated
key code 3 using {command down, option down} --- send cmd+alt+F to Sparrow invoking search
keystroke q --- enter the query
end tell
end tell
end alfred_script
also an easy link: download