Giant Lyman-alpha blobs with sizes of 50-100kpc represent dramatic episodes of on-going galaxy formation in the distant Universe. Research in the past decade has struggled to make progress on the question of what powers these huge Ly-alpha halos and whether the Ly-alpha-emitting gas is outflowing or infalling. In this talk, I will overview the recent progress in the Lya blob research, mainly based on my own works. First, I will present our deep and/or large area narrowband imaging surveys to identify tens of Lya blobs at redshifts ~2-5. These surveys have produced the first constraints on blobs' clustering and large-scale environment, showing that Lya blobs occupy massive halos likely to evolve into rich groups and clusters today. Second, we carried out large optical/NIR spectroscopic campaigns to investigate their gas kinematics. Our studies using non-resonant (optically-thin) emission lines show that there are only *weak* outflows within the blobs, therefore gas infall or extreme hyper/superwinds are not the source of the extended Ly-alpha emission. I will also present the first detection of molecular gas from a Ly-alpha blob and our on-going effort to characterize the physical conditions of its ISM. Lastly, I will discuss how the future facilities (GMT and ALMA) will play a role in revealing the nature of this mysterious sources.