intel has also recently jumped onto the bandwagon with their own distribution of hadoop:
http://hadoop.intel.com/however!OP, be wary of big data roles. although the technology is pretty cool, not every job in that space will necessarily be challenging or even interesting. a buddy of mine recently joined the data warehouse team at a company because they use hadoop extensively and he was looking to gain some exposure to it. however, 90% of his time is spent writing adhoc query reports using Pig (a dataflow language loosely akin to SQL but that relies on mapreduce to get the job done), which as you can imagine is pretty dull. so before you jump into any role being offered in this area, make sure you know what you're getting into. i am sure there are plenty of really cool roles in this space as well but just beware.you might not need to have an extensive background in hardware/networking (altho it certainly helps) because many mid-size and larger companies have dedicated syseng and techops teams to deal with the actual infrastructure+networking aspects. of course this varies from place to place and again you have to ask before joining a team what your role will entail.but yeah, there's lots of really neat stuff being done, as capafan mentioned. also look into solr and cascading if you haven't yet. google pregel is also interesting (apache giraph implements it).see:
http://googleresearch.blogspot.com/2009 ... e.htmlalso, re. the certification bit - my buddy was able to get the job without being certified because he did well on his interview. so it'll help but may not be as much of a dealbreaker for firms looking to hire, if the rest of your skillset is impressive.