Been tethered since release!
Only a few apps require a full reboot from Cydia. I havent had one instance of a random reboot or crash (to cause a reboot).
There was one episode.......(I was showing my friend how easy it is to get into DFU, then I realised I was tethered. So was he, but he used Redsn0w to Jailbreak his iPhone4. So, just for giggles, I thought I would try Redsn0w 'Just Boot' option, even though I had used Sn0wbreeze to JB my iPhone4. It appeared to work, although Redsn0w takes a lot longer to boot than Sn0wbreeze. It worked to the point my phone rebooted. But when i accessed any screens, I had the dreaded quarter screen screen size!! So I had to go home, restore my Custom Firmware, do a Restore, Sync, then install all my Cydia apps again. Since then I have had an uptime of 14 days. No reboots!)
Moral of the story is, Dont use the wrong app to reboot your tethered Jailbreak.
But, yeah, you shouldnt need to reboot your phone, unless you turn it off every night or something? Even then, with Sn0wbreeze, it takes seconds to reboot it.
To be fair, I take my USB pen and cable everywhere with me, just in case, but I havent needed it!
Take care
