Twitter is having a rough time. The Denial of Service Attack is one thing. Then Facebook goes for the jugular by spending $50M to acquire FriendFeed. I have also written about Twitter's loss of memory. Yes, our collective hive mind has disappeared, or it is being held to ransom behind the walls of fortress Twitter.
My advice to you is that a topic is worth following in your Tweetdeck or Seesmic twitter client then grab the RSS feed for the search term and drop it in to your RSS Reader. I have taken my most frequent searches and added them to my Google Reader. It is easy to do and means you can go back and search on your comments and mentions.
The Direct Messages I receive already arrive in my email inbox. The only thing I haven't found yet is a convenient way to archive my Sent Direct Messages. Does anyone have any ideas on how best to do that? I suppose I could look at using OAuth and set up a routine to regularly connect and retrieve Sent DMs.