Manifold Time is the first in Stephen Baxter's Manifold series. It recently became available as a free PDF--this blog will be on hiatus for a week or so while I read it (so little time in the day!) and I will let you know what I think of it.
Baxter's works don't quite make my very favorite list, but there are many on the Very Good list. SHEENA 5 is a preview of the above book, if you want a sample. Fubar is a cute quick read. I don't always agree with his worldview, but I like his style. More on that after Manifold Time.