No. You are limited to a single swift/immediate action per round.
Page 134. Unfortunately, by the Rules as Written this appears to be true in Beta rules.
I'm pretty conservative on issuing the House Rules, but I'm pretty sure this one will make the cut.
I think Star Wars Saga had something like that. 1 swift action as a swift action, 2 as a move action, 3 as a full-round action.
Officially...I have no idea. From the posts before me, it sounds like no. As a DM (some of the time), I'd allow it depending on the action. I don't see why someone wouldn't be able to do something that takes less time than a move action with their move action. I wouldn't allow some special abilities or spells that only take a swift action if they'd already taken one. I probably wouldn't let a Ninja/Assassin do his swift Ninja Invisibiliy and then cast a swift Assassin spell. If one of the swift actions was mundane or extraordinary, I may allow it if sounds plausable.
On reflection, Quicken Spell is probably the major barrier here. If you allowed swift actions to sub in then you could get three spells off per round.
Even if you said you could only use Quicken Spell once, there are still a ton of "Swift X" spells in the 3.5 splat books, so I'm sure someone would come up with a heinous combo to break everything.
There's a VERY good reason for NOT allowing the conversion of actions into swift actions: Swift actions are designed and implemented with the specific concept that they can only be used once per round. For example, Quickened spells are swift actions to cast. If you allow players to convert move actions into swift actions, players could easily cast three spells in a single round as a matter of course. There's a reason that Multi-Spell, which allows multiple Quickened spells per round, is an Epic Level Feat.
