Here is a tip I use to keep black swan loaded into the background on iPhone's ios 4.
1. Download a full screen web browser app that supports saved states like Pefect Browser - Fullscreen.
2. Open the following url > https://voicecentralwe.appspot.com / voicecentral.html?&browser=true&tab=sms and set as homepage. I had to put spaces in the url name in order for it to show on this forum so please remove the spaces by the forward slash.
3. Set browser to full screen and voila, multitasking black swan. Once perfect browser is open for the first time, you can then open black swan subsequent times with no loading. This is great for direct dial phone calls. It also works and looks better than GV connect and the Google Voice web app by Google.