I just listened to an interesting interview with John Barrow, a cosmologist and mathematician who talks about his book: The Infinite Book : A Short Guide to the Boundless, Timeless and Endless.
He explains how the Universe may or may not be infinity and outlines a theory where our particular Universe is finite, but there exists an infinitely old realm of unlimited parallel universes beyond ours. We will however, never know for sure, since, in order to get information from those other Universes that information would have to travel faster than the speed of light, which is, of course, impossible (according to Einstein).
This theory sounds remarkably similar to the view of the Universe given in the Srimad-Bhagavatam. Maha-Visnu is in the infinite spiritual causal ocean where time does not exist and generates unlimited finite Universes just like ours.
Barrow also explains how there are different sized infinities (as discovered by Galileo Galilei). There are, in fact, an unlimited number of infinities, each larger than the next. The infinite infinity is mathematically impossible (as shown by Georg Cantor, but hypothetically possible for a meta-physical being such as God.
There are several statements in Vedic literature that the spiritual energy is three times larger than the material energy (SB 2.6.20 and Caitanya Caritamrita Madhya-lila Chapter 21 Verses 51, 55, 56, 57, 87). Devotees always told me that these statements were not to be taken literally. I was however never satisfied with that explanation. However, using Cantor??(TM)s mathematics of infinite sets, it is indeed perfectly reasonable to talk about multiple differently sized infinities.